docs(pr-template): added code checklist

Author: kennethrioja

.github/pull_request_template.md

@@ -5,7 +5,7 @@
 **Motivation and context**
 
 (Tag any relevant issues or discussions with #, or write a brief explanation of why you are making this PR)
- 
+
 **Screenshots**
 
 (Paste or upload any relevant screenshots)
@@ -14,5 +14,18 @@
 
 - [ ] I have read and followed the [CONTRIBUTING](https://github.com/ElixirTeSS/TeSS/blob/master/CONTRIBUTING.md) guide.
 - [ ] I confirm that I have the authority necessary to make this contribution on behalf of its copyright owner and agree
-  to license it to the TeSS codebase under the 
+  to license it to the TeSS codebase under the
   [BSD license](https://github.com/ElixirTeSS/TeSS/blob/master/LICENSE).
+
+**Code checklist**
+
+- [ ] Changes are covered by tests
+- [ ] There is clear logging and error handling
+- [ ] Documentation is updated
+
+**To ease the reviewer's work**
+
+- Review your own code
+- Add context to smaller changes
+- Highlight important parts
+- Ask specific questions if needed