Support brave browser with install.sh

[mithodin]

The brave browser (https://brave.com/) now supports chrome extensions in the beta release channel and will apparently also support them in the stable release once it hits 1.0.

That means it also supports browserpass (yay!).

Therefore, the install script should try to detect brave and give the option to install the native messaging host json file in the appropriate location. So far, I have only been able to find the system-wide folder it looks at via brave/muon#259, but there should be an appropriate user location as well. If I manange to find out, I will update this issue.

[mithodin]

With the beta version of brave, ~/.config/BraveSoftware/Brave-Browser-Beta seems to be the user path in linux.

[mithodin]

I have created a pull request implementing this. #295

[maximbaz]

Thanks for the PR, let's track this work via #295 then 👍