docs: fix by proofreading

Co-authored-by: MGatner <[email protected]>

Author: kenjis

CONTRIBUTING.md

@@ -3,7 +3,7 @@
 CodeIgniter is a community driven project and accepts contributions of
 code and documentation from the community.
 
-If you'd like to contribute, please read the [Contributing to CodeIgniter](https://github.com/codeigniter4/CodeIgniter4/blob/develop/contributing/README.md)
+If you'd like to contribute, please read [Contributing to CodeIgniter](https://github.com/codeigniter4/CodeIgniter4/blob/develop/contributing/README.md)
 in the [main repository](https://github.com/codeigniter4/CodeIgniter4).
 
 If you are going to contribute to this repository, please report bugs or send PRs