feat(docs): added pull_request_template.md

[Aitthi]

PR Checklist

Please check if your PR fulfills the following requirements:

• [x] The PR follows our guidelines: https://github.com/thananon/twitch_tools/blob/main/CONTRIBUTING.md
• [ ] Tests for the changes have been added (for bug fixes / features)
• [ ] Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

Please check the one that applies to this PR using "x".

[ ] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[x] Documentation content changes
[ ] Other... Please describe:

What is the current behavior?

Issue Number: N/A

What is the new behavior?

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information