[DOC] - Consistency on usage of angle brackets for variables and urls

[kcpevey]

Preliminary Checks

• This issue is not a question, feature request, RFC, or anything other than a bug report. Please post those things in GitHub Discussions: https://github.com/nebari-dev/nebari/discussions

Summary

The docs currently have an inconsistent usage of angle brackets and curly brackets. We should pick one and go with it. After the initial suggestion from @Adam-D-Lewis, I'm in agreement with using angle brackets, < and > across all docs.

IMPORTANT: After #503 is merged, usage of the angle brackets will require escaping them with a slash, otherwise docusaurus will throw errors.

Steps to Resolve this Issue

1. Review all the docs for curly brackets
2. Switch to angle brackets

[krassowski]

Also reported in #403