Add a missing article

Author: vgvassilev

_includes/footer.html

@@ -25,7 +25,7 @@
             <a href="mailto:[email protected]">Vassil Vassilev</a>
           </p>
           <p>
-            <i>This project is supported by National Science Foundation under
+            <i>This project is supported by the National Science Foundation under
               Grant OAC-1931408 (2020-2023) and OAC-2311471(2023-2026). Any
               opinions, findings, conclusions or recommendations expressed in
               this material are those of the authors and do not necessarily