Updated PR github template

Author: MarcinOrlowski

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,17 +1,18 @@
 ### This pull request...
 
-* [ ] Fixes a bug.
+* [ ] Fixes a bug. Closes #TICKET-NUMBER
 * [ ] Adds new feature or improves existing behaviour.
 * [ ] Documentation change.
 
 ### Checklist:
 
 * [ ] I have opened the issue ticket that this pull request is part of.
-* [ ] This pull request title contains `Fixes: #{$ISSUE_NO}` that closes ticket.
+* [ ] This pull request title contains `(#TICKET-NUMBER)` for reference..
+* [ ] This pull request description contains `Closes #{$ISSUE_NO}` that closes ticket.
 * [ ] This pull request is all my own work - I have not plagiarized.
 * [ ] This contribution is licensed under MIT or compatible license.
 * [ ] All code is covered in unit tests and all tests pass.
-* [ ] I have updated the documentation that covers all the changes this pull request makes.
+* [ ] I have updated the docs to cover PR's changes (if applicable).
 * [ ] All functions and variable names follow project naming conventions.
 * [ ] All function parameters and return values are annotated with PHP [type hints](https://www.php.net/manual/en/language.oop5.typehinting.php).
 * [ ] All functions have [PHPDocs](https://docs.phpdoc.org/3.0/guide/references/phpdoc/index.html) blocks.