Docs: say which package to install, and what each one buys

[softov]

Now that 0.1.0 is on npm, the docs had to answer a question they never did: which package do I install, and what does each one get me?

The README opened with an install line and an import, and left the reader to infer the rest — that @textui/kit alone is enough to get something on screen, that Panel and Table are a second install, that the catalog resolves by name and therefore has to be registered, and that the CLI needs no install at all.

README

A new Installing section, with both npm and pnpm forms on every line:

Want	Install
Something on screen	@textui/kit — runtime, terminal, render
Panel, Table, charts, forms	+ @textui/widgets, registered via onBoot
Project setup, copied components	npx @textui/cli init — no install
Runtime without a terminal	@textui/core + @textui/terminal

The opening example now shows a complete working app — Box, Text, useState, useInput, render — all from @textui/kit, rather than a fragment referencing an undefined Dashboard.

I checked the split empirically against the published packages rather than assuming: @textui/kit and @textui/widgets have zero overlapping exports. Box/Text/hooks/render are kit; Panel/Table/Row/Column/registerBuiltins are widgets.

Getting started

Leads with @textui/kit instead of pnpm add @textui/core @textui/terminal. Those move down to The pieces underneath — which is what they are once the kit exists — and the hand-wired createApp hello goes with them. It was the first thing on the page and it is not the first thing to read.

Also notes the onBoot failure mode explicitly: forget it and nothing throws at compile time, because a missing registration is a runtime miss rendered visibly where the component should have been.

The snippets now cover kit

scripts/docs/snippets gained @textui/kit, so kit examples are typechecked like every other snippet. That immediately earned its keep — it caught a <Dashboard /> in my new prose that no snippet defined. 185 snippets check clean now.

The root README is not extracted for typechecking, so rather than leave a second hand-written variant to drift, its example is byte-identical to the verified one in getting started. I asserted that equality rather than eyeballing it.

Gate green: build, typecheck (all workspaces including snippets), docs:check, 185 snippets.