Add a short guide explaining the build and deploy flow for base/web

[gist-oily]

What is the issue you are encountering with the docs?

It’s not immediately clear how the base/web project is built and deployed from start to finish. A short overview would help contributors understand how changes make it from code to production.

Describe the solution you'd like to see.

Add a brief documentation section that explains the build steps, where configuration lives, and how deployments are triggered,