Review & Update User's Guides

Parent issue assigning reviewers to User's Guide sections.

TODO list for User's Guide reviewers:
- Start from the development version of the documentation: https://escomp.github.io/CTSM//index.html
- Test material in practice to confirm that instructions work
- Check for missing content or content that needs updating
- Check formatting, references, links, ...
- Check for already existing issues and create new issue(s) as needed and put them in the CLM documentation project (https://github.com/orgs/ESCOMP/projects/54/views/1) labeled NEXT for visibility
- Instructions for updating the documentation: https://escomp.github.io/CTSM//users_guide/working-with-documentation/index.html

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- [x] @slevis-lmwg when we have assigned all sections, change title to User's Guide Reviews.