Add Brave to the Debian repository

On Debian (based) systems Brave can only be installed by manually downloading the package or by adding the PPA. It is on the Debian package wishlist since 2017 but nobody offered to maintain it to this day. As Brave is now a popular web browser it seems appropriate for You devs to maintain it - not someone from the Debian Team. Being in the official repository strengthens the app’s position on the market and helps to popularize it even more. Users can install it easier and faster - user-friendliness - and without opening any other browser (no need to search for the PPA).