Update howto-checkbox comments

Author: robdodson

elements/howto-checkbox/README.md

@@ -23,8 +23,8 @@ is set to true or the `disabled` attribute is applied, the checkbox sets
 
 ## Reference {: #reference }
 
-- [Checkbox pattern in ARIA Authoring Practices 1.1][checkbox-pattern]
-- [What can ARIA do?][what-aria]
+- [Checkbox Pattern in ARIA Authoring Practices 1.1][checkbox-pattern]
+- [What can ARIA Do?][what-aria]
 - [Using tabindex][using-tabindex]
 
 [checkbox-pattern]: https://www.w3.org/TR/wai-aria-practices-1.1/#checkbox

elements/howto-checkbox/howto-checkbox.js

@@ -160,7 +160,7 @@
  }
 
  /**
- * `attributeChangedCallback` is called when any of the attributes in the
+ * `attributeChangedCallback()` is called when any of the attributes in the
  * `observedAttributes` array are changed. It's a good place to handle
  * side effects, like setting ARIA attributes.
  */
@@ -212,8 +212,8 @@
  }
 
  /**
- * `_toggleChecked` calls the `checked` setter and flips its state.
- * Because `_toggleChecked` is only caused by a user action, it will
+ * `_toggleChecked()` calls the `checked` setter and flips its state.
+ * Because `_toggleChecked()` is only caused by a user action, it will
  * also dispatch a change event. This event bubbles in order to mimic
  * the native behavior of `<input type=checkbox>`.
  */