pull_request_template.md

Checklist

• Source is rebased on latest upstream main so is mergeable automatically or easily merged even with confliction.
• Title of this PR is meaningful: e.g. "fix issue #8 geomPipeline.py -o does not work", not "fix geomPipeline.py"
• Commit message is meaningful: git push origin +your_branch to squash some tiny fixes for CI failures
• Give the maintainer the legal rights to change the open source license in the future (see wiki/Contribution.md) for details