Merge pull request #954 from haveneer-training/fix-mod-content

fix(move_semantics) : add move_semantics6.rs to its mod

exercises/move_semantics/mod.rs

@@ -3,3 +3,4 @@ mod move_semantics2;
 mod move_semantics3;
 mod move_semantics4;
 mod move_semantics5;
+mod move_semantics6;