Define `globalThis`, leave `global` definition as deprecated.

_layouts/index.html

@@ -13,7 +13,9 @@
     <script type='text/javascript' src='/node_modules/es6-promise/dist/es6-promise.auto.js'></script>
     <script type='text/javascript' src='the.js'></script>
     <script type='text/javascript'>
+        // TODO remove, deprecated
         var global = typeof global === "undefined" ? window : global || window;
+        var globalThis = typeof globalThis === "undefined" ? window : globalThis || window;
         new Promise(function (resolve, reject) {
             require(['app'], resolve, reject);
         }).then(function (amber) {

learn.html

@@ -9,7 +9,9 @@
     <script type='text/javascript' src='/node_modules/es6-promise/dist/es6-promise.auto.js'></script>
     <script type='text/javascript' src='the.js'></script>
     <script type='text/javascript'>
+        // TODO remove, deprecated
         var global = typeof global === "undefined" ? window : global || window;
+        var globalThis = typeof globalThis === "undefined" ? window : globalThis || window;
         new Promise(function (resolve, reject) {
             require(['app'], resolve, reject);
         }).then(function (amber) {