Add pull request template

[korikuzma]

Feature description

Similar to our issue templates, we should include a PR template to provide guidance to contributors who are creating PRs. This will standardize PR submissions and ensure all necessary information is included.

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

Use case

As a contributor making a PR, I want clear guidance on what information to include to help reviewers in their review

Acceptance Criteria

Given a contributor is preparing to create a PR
When they use the PR template
Then they should know what information is required to submit a PR

Proposed solution

No response

Alternatives considered

No response

Implementation details

No response

Potential Impact

No response

Additional context

I can create the initial PR, but would like feedback from @GenomicMedLab/wagner-lab

Contribution

Yes, I can create a PR for this feature.