[Documentation] Create a simple pull request template

[therzka]

It would be nice to create a template for contributors when they submit PRs. See resources for some examples and take a look at past PRs to see what people tend to include in their descriptions and how we can better organize/normalize that info.

Resources:

• https://docs.github.com/en/communities/using-templates-to-encourage-useful-issues-and-pull-requests/creating-a-pull-request-template-for-your-repository
• https://docs.github.com/en/communities/using-templates-to-encourage-useful-issues-and-pull-requests/about-issue-and-pull-request-templates#pull-request-templates

Examples:

• https://embeddedartistry.com/blog/2017/08/04/a-github-pull-request-template-for-your-projects/
• https://developers.soundcloud.com/blog/pr-templates-for-effective-pull-requests
• https://github.com/devspace/awesome-github-templates#rocket-templates-for-pull-requests

[blackgirlbytes]

Here's another pull request template that I think is great to use as an example: https://github.com/open-sauced/.github/blob/main/.github/PULL_REQUEST_TEMPLATE.md

[coderlore]

I would like to work on a section of this. @beverand let me know if there's a particular section you want me to work on.

[paramsiddharth]

@coderlore Make sure to check if there are existing PRs for this issue! Currently there are #489 and #497 already in review.