docs: fix Code of Conduct link in Contributing

closes expressjs#4351

Author: getspooky

Contributing.md

@@ -64,7 +64,7 @@ Anyone can become a triager! Read more about the process of being a triager in
 
 [Open an issue in `expressjs/express` repo](https://github.com/expressjs/express/issues/new)
 to request the triage role. State that you have read and agree to the
-[Code of Conduct](Code-of-Conduct.md) and details of the role.
+[Code of Conduct](Code-Of-Conduct.md) and details of the role.
 
 Here is an example issue content you can copy and paste: