Update internal docs

[tjtelan]

README.md needs instructions for

• fork-pull model
• merge with bors
  • Procedures for how to skip checks for merge (TBD)

WRITERS.md needs some words about the structure of the docs.

• Where to add things so they can adhere to the documentation structure
• How to write internal links so they get checked by Hugo at compile
• Examples of shortcodes we have installed
• Code-block strategy, and what goes in them vs what goes inside the content

[tjtelan]

For README.md, I added a diagram to document the gitops workflow, but in order for it to be more useful, we need to add automation that will render and commit it into the repo when it gets updated