docs: use Markdown for skill references (#123)

Author: chenjiahan

.agents/skills/migrate-to-rstack-cli/SKILL.md

@@ -11,13 +11,13 @@ Rstack CLI is the `rstack` package, exposed through the `rs` binaries. It provid
 
 Read every matching reference before editing. Load only the tools present in the project.
 
-- `@rsbuild/core`, `rsbuild.config.*`, `rsbuild` commands, or Rsbuild types: [rsbuild.mdx](references/rsbuild.mdx)
-- `@rslib/core`, `rslib.config.*`, `rslib` commands, or Rslib types: [rslib.mdx](references/rslib.mdx)
-- `@rstest/core`, `@rstest/adapter-*`, `rstest.config.*`, `rstest` commands, or test imports: [rstest.mdx](references/rstest.mdx)
-- `@rslint/core`, `rslint.config.*`, `rslint` commands, or lint imports: [rslint.mdx](references/rslint.mdx)
-- `@rspress/core`, `rspress.config.*`, `rspress` commands, themes, or plugins: [rspress.mdx](references/rspress.mdx)
-- `lint-staged`, `nano-staged`, their configs: [lint-staged.mdx](references/lint-staged.mdx)
-- `husky`, `.husky/`, `package.json#husky`, `simple-git-hooks`, `.simple-git-hooks.*`, or Git hook installer scripts: [git-hooks.mdx](references/git-hooks.mdx)
+- `@rsbuild/core`, `rsbuild.config.*`, `rsbuild` commands, or Rsbuild types: [rsbuild.md](references/rsbuild.md)
+- `@rslib/core`, `rslib.config.*`, `rslib` commands, or Rslib types: [rslib.md](references/rslib.md)
+- `@rstest/core`, `@rstest/adapter-*`, `rstest.config.*`, `rstest` commands, or test imports: [rstest.md](references/rstest.md)
+- `@rslint/core`, `rslint.config.*`, `rslint` commands, or lint imports: [rslint.md](references/rslint.md)
+- `@rspress/core`, `rspress.config.*`, `rspress` commands, themes, or plugins: [rspress.md](references/rspress.md)
+- `lint-staged`, `nano-staged`, their configs: [lint-staged.md](references/lint-staged.md)
+- `husky`, `.husky/`, `package.json#husky`, `simple-git-hooks`, `.simple-git-hooks.*`, or Git hook installer scripts: [git-hooks.md](references/git-hooks.md)
 
 ## Workflow
 

…e-to-rstack-cli/references/git-hooks.mdx …te-to-rstack-cli/references/git-hooks.md.agents/skills/migrate-to-rstack-cli/references/git-hooks.mdx renamed to .agents/skills/migrate-to-rstack-cli/references/git-hooks.md .agents/skills/migrate-to-rstack-cli/references/git-hooks.mdx renamed to .agents/skills/migrate-to-rstack-cli/references/git-hooks.md

@@ -1,6 +1,6 @@
 # Git Hook Migration
 
-Migrate [Husky](https://typicode.github.io/husky/) or [simple-git-hooks](https://github.com/toplenboren/simple-git-hooks#readme) to [`rs setup`](https://rstack.rs/guide/cli/setup). If a hook calls lint-staged or nano-staged, also read [lint-staged.mdx](lint-staged.mdx).
+Migrate [Husky](https://typicode.github.io/husky/) or [simple-git-hooks](https://github.com/toplenboren/simple-git-hooks#readme) to [`rs setup`](https://rstack.rs/guide/cli/setup). If a hook calls lint-staged or nano-staged, also read [lint-staged.md](lint-staged.md).
 
 ## Shared Steps
 

…to-rstack-cli/references/lint-staged.mdx …-to-rstack-cli/references/lint-staged.md.agents/skills/migrate-to-rstack-cli/references/lint-staged.mdx renamed to .agents/skills/migrate-to-rstack-cli/references/lint-staged.md .agents/skills/migrate-to-rstack-cli/references/lint-staged.mdx renamed to .agents/skills/migrate-to-rstack-cli/references/lint-staged.md

@@ -28,7 +28,7 @@ define.app(async () => {
 });
 ```
 
-If tests also use Rstest, read [rstest.mdx](rstest.mdx). `rs test` derives an Rsbuild test extension from `define.app` unless `define.test` sets `extends`.
+If tests also use Rstest, read [rstest.md](rstest.md). `rs test` derives an Rsbuild test extension from `define.app` unless `define.test` sets `extends`.
 
 ## Validate
 

…ate-to-rstack-cli/references/rsbuild.mdx …rate-to-rstack-cli/references/rsbuild.md.agents/skills/migrate-to-rstack-cli/references/rsbuild.mdx renamed to .agents/skills/migrate-to-rstack-cli/references/rsbuild.md .agents/skills/migrate-to-rstack-cli/references/rsbuild.mdx renamed to .agents/skills/migrate-to-rstack-cli/references/rsbuild.md

@@ -22,7 +22,7 @@ define.lib({
 });
 ```
 
-If tests also use Rstest, read [rstest.mdx](rstest.mdx). `rs test` derives an Rslib test extension from `define.lib` unless `define.test` sets `extends`.
+If tests also use Rstest, read [rstest.md](rstest.md). `rs test` derives an Rslib test extension from `define.lib` unless `define.test` sets `extends`.
 
 ## Validate