Update accessibility-checker-engine/help-v4/en-US/aria_toolbar_label_…

…unique.html

accessibility-checker-engine/help-v4/en-US/aria_toolbar_label_unique.html

@@ -55,7 +55,7 @@ <h3 id="ruleMessage"></h3>
 * For each element with a `"toolbar"` role, either set the value of the `aria-labelledby` attribute to the `id` value of any visible text that appropriately and uniquely describes that toolbar's purpose;
 * **Or**, use the `aria-label` attribute to add an invisible, unique, non-empty label to an element with the `"toolbar"` role.
 
-The following example shows two containers created with the ARIA `"toolbar"` role. Each container is uniquely labelled with `aria-label` and `aria-labeledby` attributes.
+The following example shows two containers created with the ARIA `"toolbar"` role. Each container is uniquely labeled with `aria-label` and `aria-labelledby` attributes.
 
 ```
 <div role="toolbar" aria-label="Simple tools">