docs: Be more precise in the PR creation description in the contributing guide.

Author: TonyCap

CONTRIBUTING.md

@@ -201,8 +201,10 @@ git rebase main
 ### 5. Submit a Pull Request
 
 1. **Push your branch to your fork**: `git push origin <type>/<brief-description>`
-2. **Create PR**: Go to the original repository on GitHub and click "New Pull Request"
-3. **Select branches**: Choose your fork's branch as the source and the original repository's `main` as the target
+2. **Create PR**: Go to the original repository on GitHub and click "New Pull Request".
+Your fork repository should also detect the changes and offer a button `Compare & pull request`
+3. **Select branches**: Choose your fork's branch as the source (`head` repository, `compare` branch)
+and the original repository's `main` as the target (`base` repository and branch)
 4. **Complete PR template**: Fill out all sections of the pull request template
 5. **Link issues**: Reference any related issues using `Fixes #123` or `Closes #456`