Added Documentation from new alias

doc/03-cli.md

@@ -706,7 +706,7 @@ performance.
 * **--apcu:** Use APCu to cache found/not-found classes.
 * **--no-dev:** Disables autoload-dev rules.
 
-## clear-cache (clearcache)
+## clear-cache / clearcache / cc
 
 Deletes all content from Composer's cache directories.