Mention logger in PR template

Author: lukaszstolarczuk

.github/pull_request_template.md

@@ -35,3 +35,4 @@ Before checking all the boxes please mark the PR as draft.
 - [ ] Extended the README/documentation
 - [ ] All newly added source files have a license
 - [ ] All newly added source files are referenced in CMake files
+- [ ] Logger (with debug/info/... messages) is used

CONTRIBUTING.md

@@ -40,8 +40,8 @@ A good practices, when opening a PR, are:
  - one PR should fix/enhance one thing, split large PR into a few smaller PRs,
  - keep commits neat and in order,
  - squash commits to include only relevant ones (no "fixes after review" or similar),
- - if a commit fixes an open issue, add in the commit message line: `Fixes #<issue_no>`
- - if a commit only mention an open issue, add in the commit message, e.g. `Ref. #<issue_no>`
+ - if a commit fixes an open issue, add in the commit message line: `Fixes #<issue_no>`,
+ - if a commit only mention an open issue, add in the commit message, e.g. `Ref. #<issue_no>`.
 
 ### Building and testing