Update docs (CONTRIBUTING.md)

[lessuselesss]

Relates to:

#1048

Risks

Low - Documentation change only, no code changes involved.

Background

What does this PR do?

Improves the branch naming documentation in CONTRIBUTING.md by:

1. Fixing nested list numbering
2. Standardizing example formatting
3. Using a clearer example number

What kind of change is this?

Improvements (misc. changes to existing features)

Documentation changes needed?

My changes require a change to the project documentation.
I have updated the documentation accordingly.

Testing

Where should a reviewer start?

Review the nested list numbering under step 3 in the "How to Contribute" section of CONTRIBUTING.md.

Detailed testing steps

1. Verify that the nested list under step 3 uses correct sequential numbering (1, 2)
2. Check that the Markdown renders correctly by:
   • Viewing the file on GitHub
   • Verifying the numbers appear as "1." and "2." in the rendered view
   • Confirming proper indentation is maintained
3. Ensure the changes maintain the document's readability and flow

The change is simple but important for maintaining professional documentation standards. The rendered view should show proper sequential numbering rather than two "1." entries.

The changes are straightforward:

3. Fork the repo and create your branch from `main`.
-    1. The name of the branch should start with the issue number and be descriptive of the changes you are making.
-    1. eg. 40--add-test-for-bug-123
+    1. The name of the branch should start with the issue number and be descriptive of the changes you are making.
+    2. Example: 9999--add-test-for-bug-123

Discord username

Adam Turner | lessuseless
ar4s_45979