Allow to choose PR template

[Jaredy899]

Our current PR template is lengthy but we may be able to choose which template to use when creating a PR.
@K1ngfish3r found this and we may want to implement it into our flow.

[NomadicCore]

In the new PR template, we have multiple different types of Pull requests

1. New package addition
2. Package update / version bump
3. Bug fix for existing package
4. Build system / tooling change
5. Documentation update
6. No Functional change
7. Other

If we can create multiple PR templates, then I think the goal should be one PR template for each of these 7 scenarios.

Ideally, we would follow the same format for each template as much as possible and only make the specific changes required for each, for a consistent experience.

The focus should be on minimising the amount of data required to be filled in to what is actually useful for reviewers to do fulfil their role.

The overall goal is to make submitting PRs as easy as possible for contributors but to provide the relevant information for reviewers to quickly review without having to go searching for information. The structure will primarily use checkboxes as this will be a way of guiding contributors to what is expected of them without taking a very hard-line stance (i.e. auto closing non-compliant PRs).