Made GitHub Releases trigger on BuildCompletion, added update submodules command and add publish script for VPS.

[EraYaN]

As you can see, the builds do trigger correctly, but skip the GitHub Release: https://dev.azure.com/jellyfin-project/jellyfin/_build/results?buildId=783

Also it does not update the submodule to latest master.

Added VPS script to be run inside jellyfin.github.io repo (with write access and setup as jellyfin-bot)

#!/bin/bash

# Download the latest release.
curl -s https://api.github.com/repos/jellyfin/jellyfin-docs/releases/latest | grep "browser_download_url.*docs-.*\.tar\.gz" | cut -d : -f 2,3 | tr -d \" | wget -O /tmp/docs.tar.gz -qi -
# Clean any old files
rm -rf docs/

mkdir -p docs/
pushd docs
# Extract the files
tar -xzf /tmp/docs.tar.gz
popd
git add docs/
git commit -m "CI Documentation update"
git push origin