Document sideMenu.openGestureMode

This property can be used to control how the SideMenu is opened using swipe gesture

bezel - only swipes from the side of the screen open the side menu
entireScreen - Swipe from any area of the screen will open the SideMenu

docs/docs/styling.md

@@ -190,6 +190,7 @@ Navigation.mergeOptions(this.props.componentId, {
     },
   },
   sideMenu: {
+    openGestureMode: 'entireScreen' | 'bezel'
     left: {
       shouldStretchDrawer: false, // defaults to true, when false sideMenu contents not stretched when opened past the width
       animationVelocity: 2500, // defaults to 840, high number is a faster sideMenu open/close animation