Add documentation

js-packages/prettier-config/README.md

@@ -1,3 +1,31 @@
 # Flarum Prettier Config
 
+Flarum's official configuration for the Prettier code formatter.
 
+For more info about shared Prettier configurations, [check out the Prettier documentation](https://prettier.io/docs/en/configuration.html#sharing-configurations).
+
+## Usage
+
+Add the `prettier` key to your `package.json`:
+
+```jsonc
+// package.json
+{
+  "name": "my-cool-package",
+  "version": "1.0.0",
+  "prettier": "@flarum/prettier-config"
+  // ...
+}
+```
+
+## Extending
+
+You can extend our config with your own custom options, too. Import our config, then spread its require in a `.prettierrc.js` file:
+
+```js
+// .prettierrc.js
+module.exports = {
+  ...require("@flarum/prettier-config"),
+  semi: false,
+};
+```

js-packages/prettier-config/package.json

@@ -1,7 +1,7 @@
 {
   "name": "@flarum/prettier-config",
   "version": "1.0.0",
-  "description": "",
+  "description": "Flarum's configuration for the Prettier code formatter.",
   "main": "prettierrc.json",
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1"