added github issue template

Adjusted the github issue template from Firecracker.

Signed-off-by: Andreea Florescu <fandree@amazon.com>

.github/pull_request_template.md

@@ -0,0 +1,24 @@
+## Reason for This PR
+
+`[Author TODO: add issue # or explain reasoning.]`
+
+## Description of Changes
+
+`[Author TODO: add description of changes.]`
+
+## License Acceptance
+
+By submitting this pull request, I confirm that my contribution is made under
+the terms of the Apache 2.0 license.
+
+## PR Checklist
+
+`[Author TODO: Meet these criteria.]`
+`[Reviewer TODO: Verify that these criteria are met. Request changes if not]`
+
+- [ ] All commits in this PR are signed (`git commit -s`).
+- [ ] The reason for this PR is clearly provided (issue no. or explanation).
+- [ ] The description of changes is clear and encompassing.
+- [ ] Any required documentation changes (code and docs) are included in this PR.
+- [ ] Any newly added `unsafe` code is properly documented.
+- [ ] Any user-facing changes are mentioned in `CHANGELOG.md`.