Run Documentation and Guides on Push for Main

[ArielSAdamsNASA]

Checklist (Please check before submitting)

• I reviewed the Contributing Guide.
• I performed a cursory search to see if the bug report is relevant, not redundant, nor in conflict with other tickets.

Describe the bug
PDFs are not generating for the Documentation and Guides workflow.

To Reproduce
https://github.com/nasa/cFS/tree/gh-pages

Expected behavior
PDFs will generate if the event is pushed to main.

Code snips
if: ${{ github.event_name == 'push' && contains(github.ref, 'main')}}

Additional context

The problem with skipping pull requests is that it won't test the merge commit. Need to skip push if it is not to the main branch.

Reporter Info
Ariel Adams, ASRC Federal