feat: add issue templates for better communication

[halamix2]

Description

Since there already is a lot of issues opened, and some of them are badly written, or duplicated I suggest taking advantage of Github's issue templates.

This way users still can create completely empty issues if they want to, but they also have a possibility of using a template, which provides some basic help in issue formatting

If labels are set in a template (e.g in bug template), they'll get added to the created issue, even if user has no ability to edit labels themselves.

You can see how it'd look at https://github.com/halamix2/source-sdk-2013/issues (press new issue and select one of the templates)

There's also possibility to add Pull Request templates

Docs: https://docs.github.com/en/communities/using-templates-to-encourage-useful-issues-and-pull-requests/about-issue-and-pull-request-templates

[halamix2]

BTW: I saw the updated contributing terms and I agree to them

[halamix2]

• Changes to the PR template were made on the main branch, and there's an another PR that refines them: #939