docs: Add CommonJS example (#23)

README.md

@@ -75,6 +75,47 @@ export default [
 ];
 ```
 
+In CommonJS format:
+
+```js
+const json = require("@eslint/json").default;
+
+module.exports = [
+ {
+ plugins: {
+ json,
+ },
+ },
+
+ // lint JSON files
+ {
+ files: ["**/*.json"],
+ language: "json/json",
+ rules: {
+ "json/no-duplicate-keys": "error",
+ },
+ },
+
+ // lint JSONC files
+ {
+ files: ["**/*.jsonc", ".vscode/*.json"],
+ language: "json/jsonc",
+ rules: {
+ "json/no-duplicate-keys": "error",
+ },
+ },
+
+ // lint JSON5 files
+ {
+ files: ["**/*.json5"],
+ language: "json/json5",
+ rules: {
+ "json/no-duplicate-keys": "error",
+ },
+ },
+];
+```
+
 ## Recommended Configuration
 
 To use the recommended configuration for this plugin, specify your matching `files` and then use the `json.configs.recommended` object, like this: