Change dockerfile entrypoint to launch evennia server, more suitable for docker-compose setups. Add websocket proxy envvar

bin/unix/evennia-docker-start.sh

@@ -0,0 +1,13 @@
+#! /bin/bash
+
+# called by the Dockerfile to start the server in docker mode
+
+# remove leftover .pid files (such as from when dropping the container)
+rm /usr/src/game/server/*.pid >& /dev/null || true
+
+# start evennia server; log to server.log but also output to stdout so it can 
+# be viewed with docker-compose logs
+exec 3>&1; evennia start 2>&1 1>&3 | tee /usr/src/game/server/logs/server.log; exec 3>&-
+
+# start a shell to keep the container running
+bash