docs: update mom6 model docs to be clear on ncar MOM6 and link to DART_interface docs

[hkershaw-brown]

Description:

This pull request changes the mom6 model_mod docs to be clear on the model_mod being developed for NCAR's version of MOM6.

I've removed term 'interface' for the model mod, since CESM has interfaces for components.
Added note on DART_interface (DART as a CESM component) with links to DART_interface documentation and crocodile workshop tutorials.

Fixes issue

fixes #1176

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

Documentation changes needed?

• My change requires a change to the documentation.
  • I have updated the documentation accordingly.

Tests

Please describe any tests you ran to verify your changes.

Checklist for merging

• Updated changelog entry
• Documentation updated
• Update conf.py

Checklist for release

• Merge into main
• Create release from the main branch with appropriate tag
• Delete feature-branch

Testing Datasets

• Dataset needed for testing available upon request
• Dataset download instructions included
• No dataset needed

[kdraeder]

Definitely an improvement and time saver for users.