✨ feat(server): Add startup script (#63)

## Description

**What issue are you solving (or what feature are you adding) and how
are you doing it?**

We start the container using supervisord, which is limiting as the user
has no way of telling the container what game to run. So, the idea is to
run like so: `docker run... ghcr.io/netrisdotme/netris/server:<tag>
netris-proton /game/yourgame.exe`


Co-authored by @djpremier

.scripts/supervisord.d/game.ini

@@ -0,0 +1,14 @@
+[program:game]
+priority=30
+autostart=false
+autorestart=true
+user=netris
+# directory=/
+command=netris-proton -r /games/AlanWake.exe
+stopsignal=INT
+logfile=/tmp/game.log
+pidfile=/tmp/game.pid
+stopsignal=INT
+autostart=true
+autorestart=true
+redirect_stderr=true