Fix spelling mistakes

src/render.c

@@ -167,7 +167,7 @@ void render_con(Con *con, bool render_fullscreen) {
                 /* By rendering the stacked container again, we handle the case
              * that we have a non-leaf-container inside the stack. In that
              * case, the children of the non-leaf-container need to be raised
-             * aswell. */
+             * as well. */
                 render_con(child, false);
             }