why does fledge operate on main instead of on feature branches?

[d-morrison]

I just stumbled onto this package yesterday, and I'm trying to understand its design. I was looking for a package that I could use with a GitHub Action to automatically bump the version and update NEWS.md on PR branches, which I would then merge into main. It seems like fledge is designed to operate only on the main branch, after you have already merged your PR - so the commit containing the version increment and NEWS.md update would come after the merge commit. This seems counter-intuitive to me; shouldn't the version change happen simultaneously with the merge? I think I'm missing a fundamental concept, but I'm not sure where to look for answers; I poked around the package website and https://happygitwithr.com/ and didn't find anything directly addressing this, but I was moving fast and might have missed it. Thanks for any recommendations!