Add Navigation page to faciliate use in MATLAB Online

1) Use an if-check in OpenOverview to try to determine if the scripts
   are opening in MATLAB Online or MATLAB Desktop and supply an
   appropriate navigation page accordingly.
2) Just in case, update Overview.html as well

Author: eszmw

HelperFunctions/Navigation.mlx

@@ -1,7 +1,13 @@
 function OpenOverview
-    % Open the overview file
+% Open the overview file
+locDir = pwd;
+if contains(locDir,filesep+"MATLAB Drive")
+    open("NavigationOverview.mlx")
+else
     open("Overview.html")
-    
-    % Close the current script
-    close(matlab.desktop.editor.getActive)
+end
+
+% Close the current script
+open("OpenOverview.m")
+close(matlab.desktop.editor.getActive)
 end