spelling: changed

Author: jsoref

lib/mixins/property-effects.html

@@ -1413,7 +1413,7 @@
        * The dirty-check is important to prevent cycles due to two-way
        * notification, but paths and objects are only dirty checked against any
        * previous value set during this turn via a "temporary cache" that is
-       * cleared when the last `_propertiesChaged` exits. This is so:
+       * cleared when the last `_propertiesChanged` exits. This is so:
        * a. any cached array paths (e.g. 'array.3.prop') may be invalidated
        *    due to array mutations like shift/unshift/splice; this is fine
        *    since path changes are dirty-checked at user entry points like `set`