Introduce a PR template based on Bevy's

[kirawi]

Objective

• Resolve Create a PR template to help improve ease of reviewing #4002

Solution

• Copied Bevy's PR format. It's simple and can also be used to automate changelogs.

[pascalkuthe]

I like this template 👍 I am not a fan of most PR templates because the tend to get in the way and are too static. This just provides a bit of structure that will make PRs a bit more uniform and easier too read without being too daunting.

We might want to introsucte a second template for trivia changes which just asks for a short description. With trivia changes I mean:

• documentation (typo fixes)
• theme changes
• langugue support (adding/changing tree sitter crammer or quieres or an LS)

[kirawi]

Perhaps that could be a follow up PR?

[pascalkuthe]

discussed this with @the-mikedavis I don't think we want contributors to add changelog entries. The rest of the template doesn't quite carry its weight.

We definitely want to expand the contributing.md and potentially add maybe pr templates for common tasks/review comments we make. I think it will need to be more tailored to our project (like one template for adding a new ts grammar/updating queries).