Add gh action for rebasing dev onto main

[erincdustin]

We need to keep the development branch in sync with main after all gh actions steps have run. Add a final step in the workflow that auto-rebases development onto main.

[robertsoniv]

We're planning on doing this for all 3 split repos, correct? It's okay you logged it here, I just wanted to make sure.

[erincdustin]

@robertsoniv ah i didn't realize i'd logged it here. for now we'll want it on storefront and admin. dotnet-functions currently has a ci gh actions workflow but not a commitizen workflow for version bump & release.

[robertsoniv]

@erincdustin shouldn't the dotnet-functions have version tags / releases? Or did we not do that because it doesn't have a package.json version to reference / update on cz bump?