Comprehensive Language Localisation for Brave Browser

Implement a thorough localisation system for Brave browser that adapts to regional language variants. This includes customising spelling, grammar, idioms, and cultural references for each locale. Extend this localisation to all aspects of the browser, including the user interface, settings menus, default search engines, and error messages. The current browser settings and options often default to American English, even when other locales are selected. This improvement would ensure that users see language variants appropriate to their region, enhancing the browsing experience and making the software feel more native to users worldwide.