Fix typo: remove extra space in README.md link

Author: MelTuc

README.md

@@ -8,7 +8,7 @@ GitHub CLI is supported for users on GitHub.com, GitHub Enterprise Cloud, and Gi
 
 ## Documentation
 
-For [installation options see below](#installation), for usage instructions [see the manual]( https://cli.github.com/manual/).
+For [installation options see below](#installation), for usage instructions [see the manual](https://cli.github.com/manual/).
 
 ## Contributing