All Examples: Add JumpTo menu button to implement WCAG bypass blocks …

…requirement (pull #1923)

Modifies examples.js to include script that adds a menu button to the top of every example page.
The menu supports moving focus to each landmark region and each H1 or H2 on the page.

cspell.json

@@ -7,6 +7,8 @@
         "npm"
     ],
     "words": [
+        "accesskey",
+        "Accesskey",
         "activedescendants",
         "affordance",
         "alertdialog",
@@ -99,6 +101,7 @@
         "jarosewli",
         "Jèrôme",
         "Jinyuan",
+        "jumpto",
         "Kasper",
         "kbdshortcuts",
         "Kowno",

examples/js/app.js

@@ -66,3 +66,14 @@
       });
   }
 })();
+
+// Add jumpto.js to examples
+(function () {
+  let ref = window.location.href.split('examples')[0];
+  if (ref) {
+    let head = document.getElementsByTagName('head')[0];
+    let scriptNode = document.createElement('script');
+    scriptNode.setAttribute('src', ref + 'examples/js/jumpto.js');
+    head.appendChild(scriptNode);
+  }
+})();