Edit yml to only build documentation when merging to main
This merge request in itself will be a good test! I created the edit-yml-edh branch and committing to it did not result in the documentation being built, which is what we want. This means that development work on candidate-release will not trigger the documentation to be built (which takes 40 minutes). Now, with the merge to main, the documentation should build. The intent of this MR is to change the gitlab-ci.yml to only build the documentation when merging to main. This seemed like the best solution. We could have it test/build the documentation with commits to main (when merge request is merged), but this runs the risk of missing issues until they are committed to main.