post release action for version number + fix docs trigger

[rem1776]

Description adds an action that will submit a pull request automatically after releases in order to add the -dev suffix to the autotools version and then assign me to review + merge it.

This might require additional permissions in the github settings (mentioned in the action page), but in my testing I was able to do it with the default settings. It always makes a new branch (with a timestamp) so shouldn't affect anything else in the repo.

One caveat is that the auto-generated PR won't run the CI workflows (at least not without additional work + messing with the tokens). Doesn't really matter though since the actual release tag will already be getting tested in the CI whenever this runs.

There is also a small bug fix here for the documentation action, apparently github thought it was a good idea to count the release trigger as three different events.

How Has This Been Tested? Here's the generated PR from my fork: https://github.com/rem1776/FMS/pull/50 i just made releases on my fork till it worked so it should be the same end result

Checklist:

• [x] My code follows the style guidelines of this project
• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [x] Any dependent changes have been merged and published in downstream xodules
• [x] New check tests, if applicable, are included
• [x] make distcheck passes