Add upgrade script

upgrades.js

@@ -0,0 +1,24 @@
+var H5PUpgrades = H5PUpgrades || {};
+
+H5PUpgrades['H5P.Essay'] = (function () {
+  return {
+    1: {
+      /**
+       * Asynchronous content upgrade hook.
+       *
+       * Add new default parameters.
+       *
+       * @param {Object} parameters
+       * @param {function} finished
+       */
+      2: function (parameters, finished, extras) {
+        parameters.media = {};
+        parameters.behaviour.pointsHost = 1;
+        parameters.ariaYourResult = 'You got @score out of @total points';
+        parameters.ariaNavigatedToSolution = 'Navigated to newly included sample solution after textarea.';
+
+        finished(null, parameters, extras);
+      }
+    }
+  };
+})();