update copyright

Author: Robert Gelb

Views/Shared/_Layout.cshtml

@@ -60,7 +60,7 @@
         <hr />
         <footer>
           <p>
-            &copy; 2018 - Robert Gelb &nbsp;
+            &copy; 2018-2021 - Robert Gelb &nbsp;
             <a href="https://twitter.com/rgelb" rel="nofollow" target="_blank">
               <img src="~/images/twitter-icon2.svg" height="32" />
             </a>