Add more typescript docs

docs/advanced/typescript.md

@@ -5,6 +5,25 @@ TODO: this feels like it’s placed weirdly.
 Where could it go?
 -->
 
+Below are some basic typings to get started with:
+
+```tsx
+declare module "@mdx-js/react" {
+  import { ComponentType, StyleHTMLAttributes } from "react"
+
+  type MDXProps = {
+    children: React.ReactNode
+    components: { wrapper: React.ReactNode }
+  }
+  export class MDXProvider extends React.Component<MDXProps> {}
+}
+```
+
+If you want to improve upon the types we would *love* a PR to
+improve the developer experience for TypeScript users.
+
+* * *
+
 If you’re getting errors from TypeScript related to imports with an `*.mdx`
 extension, create an `mdx.d.ts` file in your types directory and include it
 inside your `tsconfig.json`.