chore: import upstream snapshot with attribution

.github/PULL_REQUEST_TEMPLATE.md

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+<!--
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+Thanks a lot for your interest in contributing to Leon! :heart:
+
+Please first discuss the change you wish to make via issue,
+email, or any other method with the owners of this repository before making a change.
+It might avoid a waste of your time.
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+Before submitting your contribution, please take a moment to review this document:
+https://github.com/leon-ai/leon/blob/develop/.github/CONTRIBUTING.md
+
+Please place an x (no spaces - [x]) in all [ ] that apply.
+
+-->
+
+### What type of change does this PR introduce?
+
+- [ ] Bugfix
+- [ ] Feature
+- [ ] Refactor
+- [ ] Documentation
+- [ ] Not Sure?
+
+### Does this PR introduce breaking changes?
+
+- [ ] Yes
+- [ ] No
+
+### List any relevant issue numbers:
+
+### Description: