docs: Update README

Author: hankei6km

README.md

@@ -1,6 +1,98 @@
 # rollup-plugin-nodebox-fs-files
 
-実装中。
+Converts file to [Nodebox](https://sandpack.codesandbox.io/docs/advanced-usage/nodebox) [files](https://github.com/codesandbox/nodebox-runtime/blob/main/packages/nodebox/api.md#nodeboxfsinitfiles).
+
+## Installation
+
+```shell
+npm install --save-dev @hankei6km/rollup-plugin-nodebox-fs-files
+```
+
+## Usage
+
+```js
+// rollup.config.js
+import nodeboxFsFiles from '@hankei6km/rollup-plugin-nodebox-fs-files'
+
+export default {
+  input: 'src/index.mjs',
+  plugins: [
+    nodeboxFsFiles({
+      from: 'box-src/proj',
+      insertTo: 'src/files.mjs'
+    })
+  ]
+}
+```
+
+from
+
+```
+box-src/proj/
+├── index.js
+├── node_modules
+│   └── ...
+├── public
+│   └── image.png
+└── src
+    └── lib.js
+```
+
+to
+
+```js
+// src/files.mjs
+export const files = {
+  'index.js': 'console.log(...;\n',
+  'public/image.png': { type: 'Buffer', data: [97, 98, 99 /*...*/] },
+  'src/lib.js': 'export default ...;\n'
+}
+```
+
+> NOTE: Define a temporary `export` to bypass a linting error.
+>
+> ```js
+> // src/files.mjs
+> export const files = {}
+> ```
+
+## Examples
+
+`misc` directory is ignored.
+
+```js
+// rollup.config.js
+import nodeboxFsFiles from '@hankei6km/rollup-plugin-nodebox-fs-files'
+
+export default {
+  input: 'src/index.mjs',
+  plugins: [
+    nodeboxFsFiles({
+      from: 'box-src/proj',
+      insertTo: 'src/files.mjs',
+      excludeFrom: '**/misc/**'
+    })
+  ]
+}
+```
+
+converts `.mp4` and `.mp3` files as binary.
+
+```js
+// rollup.config.js
+import nodeboxFsFiles from '@hankei6km/rollup-plugin-nodebox-fs-files'
+
+export default {
+  input: 'src/index.mjs',
+  plugins: [
+    nodeboxFsFiles({
+      from: 'box-src/proj',
+      insertTo: 'src/files.mjs',
+      binaryFile: ['**/*.mp4', '**/*.mp3']
+    })
+  ]
+}
+```
 
 ## License