1. install these files to a convenient location, e.g. /opt/yt, and change into the directory
	git clone ... /opt/yt
	cd /opt/yt
2. create sqlite database and put filename in config.ini
	sqlite3 subscriptions.sqlite < config/setup.sql
3. install virtual environment
	python3 -m venv venv
	. venv/bin/activate
	pip3 install -r config/requirements.txt
	deactivate
4. configure everything:
	config.ini
	gunicorn-frontend-config.py -> https://docs.gunicorn.org/en/stable/settings.html
	gunicorn-webhooks-config.py
	startup.sh
4a. generate a secret key in app/frontend.py
	# replace 'app.secret_key = ...' with the output of this command:
	python3 -c 'import secrets;print(secrets.token_bytes(16))'
5. for now, edit pull-subs and update-subs to point to your venv
6. manually trigger cronjobs
	./app/refresh-cipher.pl
	./app/pull-subscriptions.py
	./app/update-subscriptions.py
7. start the web servers (it is recommended to create init/systemd files)
	./config/startup.sh
8. install cronjobs (once per day, time doesn't matter)
	YT_DIR=/opt/yt
	YT_CONFIG=/opt/yt/config/config.ini
	19 21 * * * $YT_DIR/pull-subscriptions.py
	03 13 * * * $YT_DIR/update-subscriptions.py
	52 02 * * * $YT_DIR/refresh-cipher.pl