Another bugfix for SSH keys. Hopefully the last one!

Bugfix for the SSH key feature (I am 99% sure that this will work now).

This release adds the ability to provide an SSH key to use for creating tags, which works around some limitations with the default token. See the "Personal Access Tokens" and "SSH Deploy Keys" README sections, issue #47 and PR #49 for more details.

I broke the deploy script in the last release. I think this fixes it.

Adds custom changelog template support (see the README for details).
This might be buggy, please report any errors via an issue.

New feature: Use the branches input to enable release branch management if you're using the PkgDev registration workflow (see the README for more details).
I'm like 85% sure it works properly.

Fixed a bug (I think) when looking for invalid existing tags when that existing tag was non-annotated.

Reworked internals and a few inputs/capabilities have changed. See #43 for a summary.
I think this should be pretty solid but keep your fingers crossed.

This should fix a bug that fixing a bug in the last release caused. Let's hope that this is the end of the chain.

This should fix a bug that didn't allow you to tag versions on branches other than the default branch.