Update pull request guide reference

[emmanuel-ferdman]

PR Summary

Small PR - PR updates the Github pull request reference to point to the correct guide.

Checklist:

• Add tests that demonstrate the correct behavior of the change. Tests should fail without the change.
• Add or update relevant docs, in the docs folder and in code.
• Add an entry in docs/CHANGELOG.rst, summarizing the change and linking to the issue.
• Run pre-commit hooks and fix any issues.
• Run pytest and make sure no tests failed.