feat: support type augmentation for rule options (#695)

Author: nwidynski

src/types.ts

@@ -8,7 +8,7 @@ import type { VendoredPrettierOptions } from './vender/prettier-types'
 
 export type Awaitable<T> = T | Promise<T>
 
-export type Rules = RuleOptions
+export interface Rules extends RuleOptions {}
 
 export type { ConfigNames }