chore: Reorganize files into folders

to make it plain where each file belongs in the containers file system
and to simplify the `ADD` directives in the Containerfile.

Signed-off-by: Andreas Hartmann <hartan@7x.de>

home/podman/.config/systemd/user/podman.socket

@@ -0,0 +1,11 @@
+[Unit]
+Description=Podman API Socket
+Documentation=man:podman-system-service(1)
+
+[Socket]
+ListenStream=/home/runner/podman.sock
+SocketGroup=runner
+SocketMode=0660
+
+[Install]
+WantedBy=sockets.target