Docs/Examples: Open panel on mobile when no page/example is selected.

docs/index.html

@@ -1911,6 +1911,12 @@
 
 			const selectedPage = window.location.hash.substring( 1 );
 
+			if ( selectedPage === '' ) {
+
+				panel.classList.add( 'open' );
+
+			}
+
 			const links = navigation.querySelectorAll( 'a' );
 
 			links.forEach( link => {

examples/index.html

@@ -118,6 +118,12 @@
 
 			}
 
+			if ( selected === null ) {
+
+				panel.classList.add( 'open' );
+
+			}
+
 			if ( viewer.src === '' ) {
 
 				viewer.srcdoc = document.getElementById( 'PlaceholderHTML' ).innerHTML;