Localization-for-developers.md

@@ -61,6 +61,7 @@ Release an alpha to test translations as the Tor Browser team does. For the webs
 
 Imagine a timeline a bit like this:
 ```mermaid
+%%{init: { 'theme': 'dark' } }%%
 gantt
     title Localization process
     dateFormat  YYYY-MM-DD