Add menu subheading assistive text to menu items (#3179)

* initial commit for accessible headers

* Update item.jsx

* adding groupedBy prop

* package changes reverted

Author: shrivastavaajit

components/utilities/menu-list/item.jsx

@@ -192,6 +192,9 @@ class ListItem extends React.Component {
 						role={this.props.checkmark ? 'menuitemcheckbox' : 'menuitem'}
 						tabIndex="-1"
 					>
+						{this.props.groupedBy && (
+							<span className="slds-assistive-text">{`-${this.props.groupedBy}`}</span>
+						)}
 						{this.getLabel()}
 						{this.getIcon('right')}
 					</a>

package-lock.json

@@ -2032,4 +2032,4 @@
 			"description": "The following components are prototypes. (a) Props may change within a minor release. (b) Web Content Accessibility Guidelines may not be met. (c) CSS imports may be required, since it is being added to SLDS."
 		}
 	}
-}
+}