Add podman support

[Renarde-dev]

Adding support for podman quadlets ( systemd managed podman containers ).

Ideally we should support rootless containers.

• Create basic configuration .container files to match the compose.yml
• Add relevant documentation
• See if using a .volume is a good idea
• Test containers in apparmor and SeLinux environment

[l-2-j]

I am currently running Piwigo via podman quadlets, so thought I'd review and see how this is different to my setup, and drop a few parts from my setup as suggestions in case they'd turn out to be useful.

For example, a piwigo.pod allows for easier management of all the containers with systemd as the piwigo-pod unit:

[Pod]

[Install]
# Uncomment to enable the service by default
#WantedBy=default.target

[l-2-j]

Suggested change

	[Network]
	[Network]
	Description=Piwigo network
	After=podman-user-wait-network-online.service

[l-2-j]

Suggested change

	Pod=piwigo.pod
	HealthCmd=healthcheck.sh --connect --innodb_initialized
	HealthInterval=30s
	HealthRetries=2
	HealthTimeout=10s
	HealthOnFailure=kill
	# Uncomment for automatic updates
	#AutoUpdate=registry

[l-2-j]

Suggested change

	Volume=./piwigo-data/scripts:/usr/local/bin/scripts:z
	# Remove `127.0.0.1:` if you want piwigo publicly exposed on all interfaces,
	# and/or change `8080` to the host port you want to use.
	PublishPort=127.0.0.1:8080:80
	Volume=./piwigo-data/piwigo:/var/www/html/piwigo:z
	Volume=./piwigo-data/scripts:/usr/local/bin/scripts:z
	# Set the timezone and run as unprivileged user
	Environment=TZ=... PUID=1000 PGID=1000
	Pod=piwigo.pod
	HealthCmd=wget -nv --tries=1 --spider http://127.0.0.1/ws.php?method=pwg.session.getStatus || exit 1
	HealthInterval=30s
	HealthRetries=2
	HealthTimeout=10s
	HealthOnFailure=kill
	# Uncomment for automatic updates
	#AutoUpdate=registry

[Renarde-dev]

Hi, I can't review this right now but I'm really thankful for your contribution.