fix readme heading level

README.md

@@ -108,7 +108,7 @@ purposes. The ref argument is also preserved for all internal ajax calls.
 The application uses a fairly strict Content-Security-Policy regardless of which
 mode it is accessed under.
 
-## Localization
+### Localization
 
 Localization is done using `Flask-Babel` to create or update gettext message catalogs
 the scripts in the `scripts` directory can be used. They **must** be ran from the