[develop]: Add Contributor's Guide to documentation

[gspetro-NOAA]

DESCRIPTION OF CHANGES:

This PR adds a Contributor's Guide to the docs alongside the User's Guide.
The Contributor's Guide includes general information on use of Git submodules in the UFS. This information can be adapted in a future PR to be more SRW-specific based on user needs/requests and any training we provide.
This PR also configures the docs so that Technical Documentation can be easily added at a later date.

Type of change

• This change requires a documentation update

TESTS CONDUCTED:

None required. See doc build below.

DEPENDENCIES:

N/A.

DOCUMENTATION:

All documentation.

ISSUE:

Issue #1016

CHECKLIST

• My code follows the style guidelines in the Contributor's Guide
• I have performed a self-review of my own code using the Code Reviewer's Guide
• I have commented my code, particularly in hard-to-understand areas - N/A
• My changes need updates to the documentation. I have made corresponding changes to the documentation
• My changes do not require updates to the documentation (explain). N/A
• My changes generate no new warnings
• New and existing tests pass with my changes - N/A
• Any dependent changes have been merged and published

CONTRIBUTORS (optional):

Janet Derrico @jderrico-noaa

[MichaelLueken]

Hi @gspetro-NOAA! Thank you very much for adding the Contributor's Guide to RTD! Overall, these changes look good!

I have noted that it might be best to remove the run_we2e_comprehensive_tests label until that functionality is added to the pipeline. Additionally, given their change from EMC to EPIC, I would like to give @RatkoVasic-NOAA and @chan-hoo the opportunity to update their Areas of Expertise in the code-managers.csv file, as well as adding Brian Curtis, who will be in charge of the Operational AQM/Online-CMAQ for EMC.

[MichaelLueken]

Thanks, @gspetro-NOAA, for making my requested modifications! I will go ahead and approve these changes now (will hold off on merging until the last conversation in code-managers.csv has been resolved).