docs: update

Author: antfu

examples/plugin-file-explorer/README.md

@@ -0,0 +1,68 @@
+# Example: DevTools Kit File Explorer Plugin
+
+This example shows how to build a custom Vite DevTools panel with `@vitejs/devtools-kit`.
+
+It provides a **File Explorer** dock that:
+- lists files under a target directory
+- reads file content on demand
+- writes file content in dev (websocket) mode
+- works in static mode via RPC dump files
+
+## How It Works
+
+The example has three main parts:
+
+1. Node plugin (`src/node/plugin.ts`)
+- creates RPC functions
+- registers them with `context.rpc.register(...)`
+- hosts the built UI with `context.views.hostStatic(...)`
+- registers a dock entry (`type: 'iframe'`) for the panel
+
+2. RPC functions (`src/node/rpc/functions/*`)
+- `kit-plugin-file-explorer:getInfo` (`type: 'static'`)
+- `kit-plugin-file-explorer:listFiles` (`type: 'query'`, dumped with empty args)
+- `kit-plugin-file-explorer:readFile` (`type: 'query'`, fallback `null`)
+- `kit-plugin-file-explorer:writeFile` (`type: 'action'`, dev-only behavior)
+
+3. UI app (`src/ui/main.tsx`)
+- connects using `getDevToolsRpcClient()`
+- detects backend mode (`websocket` vs `static`)
+- hides write controls in static mode
+
+## Run The Example
+
+From the `examples/plugin-file-explorer` directory (`cd examples/plugin-file-explorer`):
+
+```bash
+pnpm play:dev
+```
+
+Then open the app URL, open Vite DevTools, and switch to the **File Explorer** dock.
+
+## Static Build / Preview
+
+Build static output:
+
+```bash
+pnpm play:build
+```
+
+Preview generated static files:
+
+```bash
+pnpm play:preview
+```
+
+Static artifacts are generated under:
+
+- `playground/.vite-devtools/.devtools/.connection.json`
+- `playground/.vite-devtools/.devtools/.rpc-dump/index.json`
+- `playground/.vite-devtools/.devtools/.rpc-dump/*.json`
+
+## Notes
+
+- Default UI base: `/.plugin-file-explorer/`
+- Default target directory: `src`
+- You can override via options or env:
+  - `KIT_PLUGIN_FILE_EXPLORER_UI_BASE`
+  - `KIT_PLUGIN_FILE_EXPLORER_TARGET_DIR`