New screenshots of the current UI (title bar with the account on the right, the
redesigned Home with three rows and progress bars, My videos privacy badges, the
Channels rows and the player). Captured against the public PeerTube demo instance
(peertube2.cpy.re) so they show real CC/Blender content, as before.
Replace the placeholder-content screenshots with a demo instance that
serves real CC-licensed open movies (Blender Foundation, framatube),
so the app looks like what it is: a video player with real thumbnails,
real durations and real playback.
Rewrite the README around what a user sees: what the app is for, how
the screens look and what to press. Add the logo, five screenshots
taken against a local mock PeerTube instance with placeholder content
(no private media), and a debug-only manifest that allows plain HTTP
so those mock instances work.
