🤖 docs: convert to .mdx and auto-generate models table (#952)

## Summary

Convert all docs to `.mdx` extension and add auto-generation of the
models table from source code.

## Changes

- **Rename all `docs/*.md` to `docs/*.mdx`** for consistent MDX parsing
- **Add `scripts/gen_docs.ts`** - Bun CLI that syncs generated content:
  - `docs/models.mdx`: table generated from `knownModels.ts`
  - `docs/system-prompt.mdx`: snippet extracted from `systemMessage.ts`
- **Replace `scripts/sync_system_prompt_docs.sh`** with TypeScript
version
- **Update `fmt.mk`** to run `gen_docs.ts` on `make fmt`/`make
fmt-check`
- **Update `.prettierrc`** to use MDX parser for `docs/*.mdx`

## Generated Models Table

The table auto-updates when models in `knownModels.ts` change, showing:
- Model display name
- Full ID (provider:model)
- Aliases for quick switching
- Default marker

Custom models can still be used via `/model <provider:model_id>`.

## Validation

- `make fmt-check` passes
- `mintlify broken-links` passes

_Generated with `mux`_

Author: ammar-agent

.prettierrc

@@ -8,5 +8,13 @@
   "printWidth": 100,
   "bracketSpacing": true,
   "arrowParens": "always",
-  "endOfLine": "lf"
+  "endOfLine": "lf",
+  "overrides": [
+    {
+      "files": "docs/**/*.mdx",
+      "options": {
+        "parser": "mdx"
+      }
+    }
+  ]
 }

docs/agentic-git-identity.md docs/agentic-git-identity.mdxdocs/agentic-git-identity.md renamed to docs/agentic-git-identity.mdx

@@ -26,7 +26,9 @@ Create a separate GitHub account for your agent:
 2. Use a distinctive username (e.g., `yourname-agent`, `yourname-ai`)
 3. Use a separate email (GitHub allows plus-addressing: `yourname+ai@example.com`)
 
-<Info>This is optional but recommended. You can also use your main account with a different email/name.</Info>
+<Info>
+  This is optional but recommended. You can also use your main account with a different email/name.
+</Info>
 
 ## Step 2: Generate Classic GitHub Token
 
@@ -57,7 +59,10 @@ Add the Git identity environment variables as [Project Secrets](/project-secrets
 
 These environment variables will be automatically injected when the agent runs Git commands in that project.
 
-<Info>If you need the agent identity outside of mux, you can alternatively set these as global environment variables in your shell configuration (`~/.zshrc`, `~/.bashrc`, etc.)</Info>
+<Info>
+  If you need the agent identity outside of mux, you can alternatively set these as global
+  environment variables in your shell configuration (`~/.zshrc`, `~/.bashrc`, etc.)
+</Info>
 
 ## Step 4: Configure GitHub Authentication
 
@@ -101,4 +106,7 @@ git config --global credential.helper ""
 git config --global --add credential.helper '!gh auth git-credential'
 ```
 
-<Warning>The "replace all" approach will disable platform keychain helpers and may break Git authentication for non-GitHub remotes (GitLab, Bitbucket, etc.).</Warning>
+<Warning>
+  The "replace all" approach will disable platform keychain helpers and may break Git authentication
+  for non-GitHub remotes (GitLab, Bitbucket, etc.).
+</Warning>

docs/benchmarking.md docs/benchmarking.mdxdocs/benchmarking.md renamed to docs/benchmarking.mdx

@@ -152,7 +152,9 @@ Remove oldest 50% of messages.
 
 ### OpenAI Responses API Limitation
 
-<Warning>`/truncate` does not work with OpenAI models due to the Responses API architecture:</Warning>
+<Warning>
+  `/truncate` does not work with OpenAI models due to the Responses API architecture:
+</Warning>
 
 - OpenAI's Responses API stores conversation state server-side
 - Manual message deletion via `/truncate` doesn't affect the server-side state

docs/cli.md docs/cli.mdxdocs/cli.md renamed to docs/cli.mdx

@@ -22,7 +22,10 @@ Download pre-built binaries of `main` from [GitHub Actions](https://github.com/c
   - `macos-dmg-arm64` (Apple Silicon)
 - **Linux**: AppImage (portable, works on most distros)
 
-<Info>Windows builds are only available from [releases](https://github.com/coder/mux/releases), not from development builds.</Info>
+<Info>
+  Windows builds are only available from [releases](https://github.com/coder/mux/releases), not from
+  development builds.
+</Info>
 
 To download:
 
@@ -57,11 +60,17 @@ The app is code-signed and notarized by Apple, so it will open without security
 3. Follow the installation prompts
 4. Launch Mux from the Start menu or desktop shortcut
 
-<Warning>Windows support is currently in alpha. Please [report any issues](https://github.com/coder/mux/issues) you encounter.</Warning>
+<Warning>
+  Windows support is currently in alpha. Please [report any
+  issues](https://github.com/coder/mux/issues) you encounter.
+</Warning>
 
 ### Testing Pre-Release Builds
 
-<Warning>Only builds from the `main` branch are signed and notarized. If you're testing a build from a pull request or other branch, you'll need to bypass macOS Gatekeeper:</Warning>
+<Warning>
+  Only builds from the `main` branch are signed and notarized. If you're testing a build from a pull
+  request or other branch, you'll need to bypass macOS Gatekeeper:
+</Warning>
 
 1. After installing, open Terminal
 2. Run: `xattr -cr /Applications/Mux.app`