docs(github): add PR template

Author: difernandez

.github/pull_request_template.md

@@ -0,0 +1,27 @@
+### Motivation / Background
+
+<!--
+Describe why this Pull Request needs to be merged. What bug have you fixed? What feature have you added? Why is it important?
+If you are addressing a specific issue (a bug or a feature request), include "Closes #ISSUE" (replace with the issue number, remove the quotes) and the issue will be linked to this PR.
+-->
+
+This Pull Request has been created because [REPLACE ME]
+
+### Detail
+
+This Pull Request changes [REPLACE ME]
+
+### Additional information
+
+<!-- Provide additional information such as benchmarks, reference to other repositories, screenshots or alternative solutions. -->
+
+### Checklist
+
+Before submitting the PR make sure the following are checked:
+
+* [ ] This Pull Request is related to one change. Changes that are unrelated should be opened in separate PRs.
+* [ ] Commit message has a concise description of what changed and why.
+* [ ] Tests are added or updated if you fix a bug or add a feature.
+* [ ] Documentation has been added or updated if you add a feature or modify an existing one.
+* [ ] CHANGELOG files are updated for the changed libraries if there is a behavior change or additional feature (under the "Unreleased" heading if this is not a version change).
+* [ ] My changes don't introduce any linter rule violations.