wrangler init should populate example code

After running wrangler init, no example code is provided (index.js or index.ts depending if they asked for TypeScript or not). It should populate a basic starter file. In the future, we can make this more complex by introducing different templates to choose from.

src/index.ts:

export default {
  async fetch(request: Request, env: Environment, ctx: ExecutionContext): Promise<Response> {
    return new Response("Hello!");
  }
}

export type Environment = {
  // MY_NAMESPACE: KvNamespace;
}

src/index.js:

export default {
  async fetch(request, env, ctx) {
    return new Response("Hello!");
  }
}

Also, should probably have a comment that links to the reference documentation?

[threepointone]

https://github.com/cloudflare/wrangler2/pull/372

[threepointone]

I like the idea of an entry point. Ok let’s try something and see how it feels.