Add links to why web

Author: RoyalIcing

apps/components_guide_web/lib/components_guide_web/templates/web/intro.html.md

@@ -1,2 +1,7 @@
 # Why do we have the web?
 
+## Where?
+
+- [Browsers](https://developer.mozilla.org/en-US/docs/Web)
+- [Deno](https://doc.deno.land/builtin/stable)
+- [Cloudflare Workers](https://developers.cloudflare.com/workers/runtime-apis/web-standards)