Set v2.0.0-beta.1 version, beta flag and changelog.

Author: microbit-carlos

CHANGELOG

@@ -1,3 +1,9 @@
+2.0.0-beta.1
+------------
+* Added WebUSB functionality (#99)
+* Added MicroPython file system functionality (#88)
+* Added autocompletion to the code editor (#185)
+
 1.1.5
 -----
 * Add floating help panel (#115)

editor.html

@@ -77,7 +77,7 @@
         </script>
         <script type="application/javascript">
             // VERSION INFORMATION
-            EDITOR_VERSION = "1.1.5";
+            EDITOR_VERSION = "2.0.0-beta.1";
             UPY_VERSION = "1.0.1";
         </script>
         <script id="files-template" type="x-tmpl-mustache">
@@ -423,7 +423,7 @@ <h2>Flashing micro:bit</h2>
       'snippets': true,
       'share': false,
       'options': true,
-      'experimental': false,
+      'experimental': true,
     },
 });
         </script>