This commit makes the entrypoint copy the client's dist files to
the mountpoint of the app-assets named volume. That way, changed
files are made available to the nginx container when the peertube
image gets updated
Closes: #8
missing:
* live streaming and RTMP proxying with traefik
* webseed cross-instance redundancy
* option to use S3-compatible storage
* testing, there might be silly bugs
Did I mention this is untested?