fix docker-compose docs styling
Created by: ggilmore
This PR:
- adds a link to the docker-compose index page to the sidebar (I didn't realize there was a dedicated sidebar template)
- changes all the lists on the docker compose docs to be unordered, and unindents all the code blocks. Our current markdown parser https://github.com/russross/blackfriday isn't able to correctly render lists with nested code blocks (numbering restarts or is otherwise broken). Switching to unordered lists + unindenting the code blocks hides this issue even though this isn't as readable as it could be.
Side note: Can we switch from https://github.com/russross/blackfriday to https://github.com/yuin/goldmark/ ? Hugo even made the switch late last year.