Add GitHub Copilot in Slack wiki page

GitHub/copilot-slack.md

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+# GitHub Copilot in Slack
+
+GitHub Copilot in Slack lets you work with the GitHub app directly from Slack. You can ask coding questions, turn a Slack discussion into a GitHub issue, and ask Copilot to make repository changes without leaving the conversation.
+
+> **Note:** GitHub documents this feature as a **public preview**, so the exact prompts and UI may change over time.
+
+## What you need first
+
+Before you can use Copilot in Slack, make sure you have:
+
+- A GitHub account
+- Access to GitHub Copilot through a paid plan, either from your own license or through organization-managed access
+- A Slack account in the workspace where you want to use it
+- The GitHub app for Slack installed in that workspace
+
+If your workspace uses Slack Enterprise Grid or your repositories are owned by an organization, a Slack or GitHub admin may need to install and configure the GitHub app first.
+
+## Install and set up the GitHub app in Slack
+
+### 1. Install the GitHub app in Slack
+
+The GitHub integration only needs to be installed once per Slack workspace.
+
+1. Go to [slack.github.com](https://slack.github.com/)
+2. Click **Add to Slack**
+3. Sign in to Slack if prompted
+4. Approve the requested permissions
+5. In any channel where you want to use the app, run `/invite @github`
+
+### 2. Connect Slack to your GitHub account
+
+Once the app is installed:
+
+1. Open a direct message with the **GitHub** app in Slack, or mention Copilot in a thread
+2. Send a message such as `login` or `/github signin`
+3. Follow the authorization prompts in Slack and GitHub
+
+GitHub's documentation notes that your first attempt to use Copilot may automatically prompt you to connect your account.
+
+### 3. Set the repository Copilot should use
+
+The first time you use Copilot in Slack, set a default repository for pull requests and related actions.
+
+- Use the **Configure settings** button if Slack shows it
+- Or use the `settings` command in the GitHub app conversation
+- Choose the repository you want Copilot to work in by default
+
+To ask Copilot to make changes in a repository, you generally need **write access** to that repository. To create issues, you need permission to create issues there.
+
+## Permissions and integrations
+
+When the GitHub app is installed in Slack, it requests permissions that let it:
+
+- Add the `/github` slash command
+- Post GitHub notifications and responses in Slack
+- Render GitHub link previews
+- Read and write certain GitHub resources on your behalf after you connect your account
+
+GitHub's Slack permissions reference specifically calls out:
+
+- **Read access to code**
+- **Read access** to actions, checks, discussions, issues, pull requests, and related metadata
+- **Write access** to issues, pull requests, deployments, and workflows
+- **Write access to content** so Copilot can open pull requests it authors
+
+If you are using enterprise-managed repositories, an administrator may also need to allow the Slack GitHub app to access the repositories you want Copilot to use.
+
+## Basic usage
+
+You can use the GitHub app in Slack in two main ways:
+
+### Ask Copilot questions
+
+Use a direct message with the GitHub app or mention Copilot in a Slack thread to ask for help with:
+
+- Explaining code
+- Summarizing a bug report or discussion
+- Suggesting implementation steps
+- Drafting documentation or issue text
+
+### Create issues from Slack
+
+Ask Copilot to turn a Slack conversation into a GitHub issue. Copilot can draft:
+
+- A title
+- A description
+- Suggested labels
+- Suggested assignees
+
+Review the draft before creating the issue.
+
+### Ask Copilot to make repository changes
+
+Copilot can use the Slack thread as context, then propose changes and open a pull request. You can optionally tell it which repository and branch to use.
+
+## Example commands and interactions
+
+### Standard GitHub app commands
+
+```text
+/github help
+/github signin
+/github subscribe FRCTeam3255/Wiki
+/github open FRCTeam3255/Wiki
+```
+
+### Example Copilot prompts
+
+```text
+@GitHub Explain what this error means and suggest the most likely fix.
+```
+
+```text
+@GitHub In FRCTeam3255/Wiki, create an issue to document how mentors should review pull requests.
+```
+
+```text
+@GitHub Add a new section to the README in repo=FRCTeam3255/Wiki branch=main that links to the GitHub folder docs.
+```
+
+```text
+@GitHub Summarize the decisions made in this thread and turn them into a checklist for implementation.
+```
+
+## Best practices
+
+- **Keep one topic per thread.** Copilot uses thread context, so focused threads produce better results.
+- **Use a direct message for cleaner context.** This is helpful when the channel thread has side conversations.
+- **Be explicit about the repository.** If there is any doubt, include `owner/repo` in your prompt.
+- **Review generated issues and pull requests carefully.** Copilot can make mistakes.
+- **Avoid sharing sensitive information in prompts.** Slack thread content may be used as context for the generated work.
+
+## Troubleshooting tips
+
+- If the GitHub app is not available in a channel, run `/invite @github`
+- If Slack says your GitHub account is not connected, run `/github signin`
+- If mentions or actions stop working, try `/github signout` and then `/github signin`
+- If Copilot targets the wrong repository, update the default repository in the app's settings
+- If Copilot cannot create changes, confirm that you have the required repository permissions
+- If you are unsure which mention format to use, type `@` in Slack and select the GitHub app from the autocomplete list; if mentions still fail, open a direct message with the GitHub app and continue there instead
+
+## Official documentation
+
+- [Integrating GitHub with Slack](https://docs.github.com/en/integrations/how-tos/slack/integrate-github-with-slack)
+- [Using GitHub in Slack](https://docs.github.com/en/integrations/how-tos/slack/use-github-in-slack)
+- [Permissions for GitHub in Slack](https://docs.github.com/en/integrations/reference/slack-permissions)
+- [Integrating Copilot cloud agent with Slack](https://docs.github.com/en/copilot/how-tos/use-copilot-agents/coding-agent/integrate-coding-agent-with-slack)