Add release type checkboxes to PR template

[bellerbrock]

…emplate

Description

Adds four release type checkboxes to the PR template and updates actions to make use of them.
Also simplifies change type checkboxes to match release note structure.

Releases can now triggered three ways:

• When a PR is merged with a release type checkbox checked, it triggers a release of the corresponding type.
• Releases can also be triggered manually by using workflow dispatch (release type is taken as an argument).
• The release action is also scheduled to check once a week (Monday 3pm EST) if there have been changes to the app directory since the last release, if it finds any it makes a new patch release.

Type of change

• CHANGE (fix or feature that would cause existing functionality to not work as expected)
• FEATURE (non-breaking change which adds functionality)
• BUGFIX (non-breaking change which fixes an issue)
• ENHANCEMENT (non-breaking change which improves existing functionality)
• NONE (if none of the other choices apply. Example, tooling, build system, CI, docs, etc.)

Checklist:

• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have updated relevant documentation

Changelog entry