docs: shorten the README hero, add key features and a one-prompt quickstart

[nvquanghuy]

Follow-up to #26.

Hero

• Tagline now matches the repo description and the social preview image: "Open-source framework for building trusted custom BI apps". The previous taglines are kept in an HTML comment as alternatives.
• The intro paragraphs move out of the hero into a new "What is anfra?" section after the demo image, so the image shows without scrolling.
• Adds "Built by the team behind Holistics and dbdiagram.io." under the links.

Key features

A new section after "Why anfra?", split by audience:

• For data teams: metrics defined once as code, every number can be inspected, your warehouse and infrastructure.
• For people building and using apps: any layout, interactions built in, live data.

Quickstart

• Adds "Fastest start: one prompt" at the top: a prompt to paste into Claude Code, Codex or Cursor that installs anfra, connects the reader's database (they enter credentials themselves), models a few tables, builds a first app and runs the server. The manual steps follow under "Or step by step".
• Step 1 mentions --agent cursor and npx skills add holistics/anfra-skills for other agents.
• Step 2 now says what anfra init creates: the models/, datasets/ and apps/ folders and .anfra/data_sources.yml, which is added to .gitignore. The setup-repo prompt in that step is dropped, since the one-prompt start covers it.

Name

The product name is written as lowercase "anfra" throughout the README, matching the logo. In-page anchors are unchanged.

🤖 Generated with Claude Code

[gemini-code-assist]

Code Review

This pull request updates the README.md to use lowercase branding for "anfra" and adds sections on key features and team background. The reviewer feedback highlights several grammatical issues where sentences incorrectly start with a lowercase letter due to this branding change, and offers rephrasing suggestions to maintain proper capitalization.

[gemini-code-assist]

Starting a sentence with a lowercase letter is grammatically incorrect. To respect the lowercase branding of anfra while maintaining proper sentence capitalization, we can rephrase the sentence slightly.

Suggested change

	Build with AI coding agents using your own HTML, JavaScript, and charting libraries. anfra SDK connects your app to a governed semantic foundation with consistent, reusable metrics and trusted business context.
	Build with AI coding agents using your own HTML, JavaScript, and charting libraries. The anfra SDK connects your app to a governed semantic foundation with consistent, reusable metrics and trusted business context.

[gemini-code-assist]

Starting a sentence with a lowercase letter is grammatically incorrect. To respect the lowercase branding of anfra while maintaining proper sentence capitalization, we can rephrase the sentence slightly.

Suggested change

	anfra sits between your app and your semantic layer. It isn't a semantic layer itself: the SDK runs in your page, and the server turns each click into a query on the metrics your semantic layer defines.
	The anfra framework sits between your app and your semantic layer. It isn't a semantic layer itself: the SDK runs in your page, and the server turns each click into a query on the metrics your semantic layer defines.

[gemini-code-assist]

Starting a sentence with a lowercase letter is grammatically incorrect. To respect the lowercase branding of anfra while maintaining proper sentence capitalization, we can rephrase the sentence slightly.

Suggested change

	anfra runs on **your semantic layer**: your models, datasets, and metrics, defined as code. anfra ships with [AMQL](https://amql.org) built in. Support for external semantic layers such as dbt, Cube, Snowflake and Databricks is planned ([details](#faq)).
	The framework runs on **your semantic layer**: your models, datasets, and metrics, defined as code. It ships with [AMQL](https://amql.org) built in. Support for external semantic layers such as dbt, Cube, Snowflake and Databricks is planned ([details](#faq)).

[gemini-code-assist]

Starting a sentence with a lowercase letter is grammatically incorrect. To respect the lowercase branding of anfra while maintaining proper sentence capitalization, we can rephrase the sentence slightly.

Suggested change

	**3. A user clicks "APAC".** anfra Server adds the filter to the trend query and runs this SQL (PostgreSQL, with time zone handling trimmed):
	**3. A user clicks "APAC".** The anfra Server adds the filter to the trend query and runs this SQL (PostgreSQL, with time zone handling trimmed):

[gemini-code-assist]

Starting a sentence with a lowercase letter is grammatically incorrect. To respect the lowercase branding of anfra while maintaining proper sentence capitalization, we can rephrase the sentence slightly.

Suggested change

	anfra Cloud is our hosted product, built on the same open-source engine. It adds what a team needs to share apps: users and SSO, row-level permissions, hosted apps with sharing links, audit logs and version history.
	Our hosted product, anfra Cloud, is built on the same open-source engine. It adds what a team needs to share apps: users and SSO, row-level permissions, hosted apps with sharing links, audit logs and version history.

[gemini-code-assist]

Starting a sentence with a lowercase letter is grammatically incorrect. To respect the lowercase branding of anfra while maintaining proper sentence capitalization, we can rephrase the sentence slightly.

Suggested change

	Those give you a framework to write the app in. anfra gives you a semantic backend for any front end the agent writes: plain HTML/JS, no Python runtime, no fixed component set. Metrics and interactions are defined once and shared across every app.
	Those give you a framework to write the app in. In contrast, anfra gives you a semantic backend for any front end the agent writes: plain HTML/JS, no Python runtime, no fixed component set. Metrics and interactions are defined once and shared across every app.

[gemini-code-assist]

Starting a sentence with a lowercase letter is grammatically incorrect. To respect the lowercase branding of anfra while maintaining proper sentence capitalization, we can rephrase the sentence slightly.

Suggested change

anfra is built to replace dashboard BI tools, not to sit beside them. Those tools were designed for building reports by hand in a fixed grid of charts and filters. With a coding agent, your team can build the app they actually need, and anfra keeps it governed: metrics are defined once in the semantic layer, and every number can be inspected back to its query and definition. anfra Cloud adds users, permissions and sharing.

We built anfra to replace dashboard BI tools, not to sit beside them. Those tools were designed for building reports by hand in a fixed grid of charts and filters. With a coding agent, your team can build the app they actually need, and anfra keeps it governed: metrics are defined once in the semantic layer, and every number can be inspected back to its query and definition. anfra Cloud adds users, permissions and sharing.

[gemini-code-assist]

Starting a sentence with a lowercase letter is grammatically incorrect. To respect the lowercase branding of anfra while maintaining proper sentence capitalization, we can rephrase the sentence slightly.

Suggested change

	Not today. anfra ships with AMQL. We plan to support other semantic layers such as Cube, dbt, Snowflake and Databricks, though advanced interactions like funnels and period comparisons will depend on AMQL.
	Not today. The anfra platform ships with AMQL. We plan to support other semantic layers such as Cube, dbt, Snowflake and Databricks, though advanced interactions like funnels and period comparisons will depend on AMQL.

[gemini-code-assist]

Starting a sentence with a lowercase letter is grammatically incorrect. To respect the lowercase branding of anfra while maintaining proper sentence capitalization, we can rephrase the sentence slightly.

Suggested change

	Queries run on your warehouse, and the anfra server sends results straight to the page. Apps don't store query results or warehouse credentials by default. anfra doesn't include an AI model: you use your own coding agent, so what the agent can see depends on what you connect it to.
	Queries run on your warehouse, and the anfra server sends results straight to the page. Apps don't store query results or warehouse credentials by default. The platform doesn't include an AI model: you use your own coding agent, so what the agent can see depends on what you connect it to.

[gemini-code-assist]

Starting a sentence with a lowercase letter is grammatically incorrect. To respect the lowercase branding of anfra while maintaining proper sentence capitalization, we can rephrase the sentence slightly.

Suggested change

	anfra is built by the team behind Holistics, and AMQL is the semantic layer Holistics runs on. anfra is a separate open-source project, licensed under Apache 2.0, and doesn't need a Holistics account. Your models and apps are plain files in your own repository, and AMQL compiles to SQL you can read.
	The team behind Holistics built anfra, and AMQL is the semantic layer Holistics runs on. As a separate open-source project licensed under Apache 2.0, anfra doesn't need a Holistics account. Your models and apps are plain files in your own repository, and AMQL compiles to SQL you can read.