Fix spelling of "guidelines" @ README (#470)

Co-authored-by: Tom Hu <88201630+thomasrockhu-codecov@users.noreply.github.com>

Author: webknjaz

README.md

@@ -283,7 +283,7 @@ The CLI can perform basic static analysis on Python code today. This static anal
 
 # Contributions
 
-This repository, like all of Codecov's repositories, strives to follow our general [Contributing guidlines](https://github.com/codecov/contributing). If you're considering making a contribution to this repository, we encourage review of our Contributing guidelines first. 
+This repository, like all of Codecov's repositories, strives to follow our general [Contributing guidelines](https://github.com/codecov/contributing). If you're considering making a contribution to this repository, we encourage review of our Contributing guidelines first. 
 
 ## Requirements