Update shell.nix

Author: Xpirix

shell.nix

@@ -25,7 +25,7 @@ in
     # Now we can execute any commands within the virtual environment.
     # This is optional and can be left out to run pip manually.
     shellHook = ''
-      echo "QGIS Plugins"
+      echo "QGIS Certification"
       echo "_________________________________________________________"
       echo "Command : Description"
       echo "_________________________________________________________"