added a missing 'auto function' comment to the cpp.snippet file

Author: MatteoGaetzner

snippets/cpp.snippets

@@ -216,6 +216,7 @@ snippet try
 	}catch(${1}) {
 
 	}
+# auto function
 snippet af auto function
 	auto ${1:name}(${2}) -> ${3:void}
 	{