Allow first commit to main

[camposandro]

This pull request solves an inconvenient issue about commits to main. With the current version of the template we install pre-commit hooks on the .prepare_project bash script. One of the hooks protects unintentional commits to main, which is extremely useful during development, but problematic when first creating a repository.

As a workaround, the last stage of the script now includes a commit to the initial branch and for that we skip the "no-commit-to-branch" hook. The documentation was updated accordingly. Closes #331.

Checklist

• [X] This PR is meant for the lincc-frameworks/python-project-template repo and not a downstream one instead.
• [X] This change is linked to an open issue
• [X] This change includes integration testing, or is small enough to be covered by existing tests

[drewoldag]

This looks very promising. I'll take a closer look when I'm at my desk.

[drewoldag]

I just ran this locally, and it worked great. Thanks for putting this together!