firefox/remote/cdp/test/browser/README.md

Update chrome-remote-interface.js

Upstream instructions on https://github.com/cyrus-and/chrome-remote-interface#using-vanilla-javascript:

% git clone https://github.com/cyrus-and/chrome-remote-interface.git
% cd chrome-remote-interface
% npm install
% TARGET=var DEBUG=true npm run webpack
% cp chrome-remote-interface.js ../