Rename main(C).c to Plus One - Solution.c

Author: JRS296

Arrays & Strings/#66 - Plus One - Easy/main(C).c renamed to Arrays & Strings/#66 - Plus One - Easy/Plus One - Solution.c

@@ -42,4 +42,4 @@ int main(){
     }
     printf("%d]",ret_arr[returnSize-1]);
     free(ret_arr);
-}
+}