doc: improve description style and add link to forum

Author: kenjis

contributing/pull_request.md

@@ -2,17 +2,23 @@
 
 ## Contributions
 
-We expect all contributions to conform to our
-[style guide](https://github.com/codeigniter4/CodeIgniter4/blob/develop/contributing/styleguide.md),
-be commented (inside the PHP source files), be documented (in the
-[user guide](https://codeigniter4.github.io/userguide/)), and unit tested (in
-the [test folder](https://github.com/codeigniter4/CodeIgniter4/tree/develop/tests)).
-
-Note, we expect all code changes or bug-fixes to be accompanied by one or more tests added to our test suite
-to prove the code works. If pull requests are not accompanied by relevant tests, they will likely be closed.
+We expect all contributions to
+- conform to our [style guide](./styleguide.md),
+- be commented (inside the PHP source files),
+- be documented (in the [user guide](https://codeigniter4.github.io/userguide/)),
+- and unit tested (in the [test folder](https://github.com/codeigniter4/CodeIgniter4/tree/develop/tests)).
+
+> [!NOTE]
+> We expect all code changes or bug-fixes to be accompanied by one or more tests
+> added to our test suite to prove the code works.
+
+If pull requests are not accompanied by relevant tests, they will likely be closed.
 Since we are a team of volunteers, we don't have any more time to work on the framework than you do. Please
-make it as painless for your contributions to be included as possible. If you need help with getting tests
-running on your local machines, ask for help on the forums. We would be happy to help out.
+make it as painless for your contributions to be included as possible.
+
+If you need help with getting tests running on your local machines, ask for help
+on the [forum](https://forum.codeigniter.com/forumdisplay.php?fid=27). We would
+be happy to help out.
 
 The [Open Source Guide](https://opensource.guide/) is a good first read for those new to contributing to open source!