Add pull request template. [ci skip]

.github/PULL_REQUEST_TEMPLATE/pull_request.md

@@ -0,0 +1,19 @@
+---
+name: Pull request
+about: Submit a pull request for this project
+title: ''
+assignees: fabiocaccamo
+
+---
+
+**Describe your changes**
+?
+
+**Related issue**
+?
+
+**Checklist before requesting a review**
+- [ ] I have performed a self-review of my code.
+- [ ] I have added torough tests for the proposed changes.
+- [ ] I have run the tests and there are not errors.
+- [ ] I have updated translations.