Update copyright date range in license

Author: delphidabbler

Docs/License.html

@@ -5,7 +5,7 @@
  * v. 2.0. If a copy of the MPL was not distributed with this file, You can
  * obtain one at http://mozilla.org/MPL/2.0/
  *
- * Copyright (C) 2012-2020, Peter Johnson (gravatar.com/delphidabbler).
+ * Copyright (C) 2012-2021, Peter Johnson (gravatar.com/delphidabbler).
  *
  * CodeSnip license.
 -->
@@ -225,7 +225,7 @@ <h2>
     Executable Program
   </h2>
   <p>
-    DelphiDabbler <em>CodeSnip</em> is copyright &copy; 2005-2020 by <a
+    DelphiDabbler <em>CodeSnip</em> is copyright &copy; 2005-2021 by <a
       href="https://gravatar.com/delphidabbler"
     >Peter D Johnson</a>.
   </p>
@@ -335,7 +335,7 @@ <h2>
       <div>
         This condition applies to all files in the
         <kbd>Src/Res/Img/Branding</kbd> directory, all of which are original
-        work copyright &copy; 2012-2020 by <a
+        work copyright &copy; 2012-2021 by <a
           href="https://gravatar.com/delphidabbler"
         >Peter D Johnson</a>.
       </div>