Expose URL of the deployment as environment variable, say DENO_URL

[tchief]

Thanks for the Deno!

I added DENO_URL environment variable to several Deno projects so far to point to the deployment URL. Would be nice to have this one automatically exposed for Deno Deployments, similar to VERCEL_URL.

Is there a particular place in codebase where DENO_DEPLOYMENT_ID or DENO_REGION are set? It seems to be out of denoland org.