docs: fix typo in contributing.md

Author: Zanadar

CONTRIBUTING.md

@@ -30,7 +30,7 @@ If you report a bug, please follow these guidelines:
 
 For small documentation changes, you can use [Github's editing feature](https://help.github.com/articles/editing-files-in-another-user-s-repository/).
 The only thing to keep in mind is to prefix the commit message with "docs: ".
-The detault commit message generated by Github will lead to a failing CI build.
+The default commit message generated by Github will lead to a failing CI build.
 
 For larger updates to the documentation
 it might be better to follow the [instructions for contributing code below](#contributing-code).