Add MPL2 boilerplate header comment

Fixes #36

Author: delphidabbler

Src/FirstRun.FmWhatsNew.FrHTML.pas

@@ -1,3 +1,14 @@
+{
+ * This Source Code Form is subject to the terms of the Mozilla Public License,
+ * v. 2.0. If a copy of the MPL was not distributed with this file, You can
+ * obtain one at https://mozilla.org/MPL/2.0/
+ *
+ * Copyright (C) 2020-2021, Peter Johnson (gravatar.com/delphidabbler).
+ *
+ * Frame that displays HTML of "what's new" message in a TWebBrowser control.
+}
+
+
 unit FirstRun.FmWhatsNew.FrHTML;
 
 interface