Fix typo in description of Project 7.11

Author: chabulhwi

07/projects/11/README.md

@@ -7,7 +7,7 @@ Enter a first and last name: Lloyd Fosdick
 Fodsick, L.
 ```
 
-The user's input may contain extre spaces before the first name, between the
+The user's input may contain extra spaces before the first name, between the
 first and last names, and after the last name.
 
 ### Solution