added .env.example and init.sh script

docker-compose.yml

@@ -1,16 +1,16 @@
 services:
   csdm_1:
     build: .
-    container_name: csdm-1
+    container_name: csdm
     ports:
-      - "27015:27015/udp"
-      - "27020:27020/udp"
+      - "${PORT}:${PORT}/udp"
+      - "${HLTV_PORT}:${HLTV_PORT}/udp"
     restart: unless-stopped
     environment:
-      MAP: "de_dust2"
-      MAXPLAYERS: "32"
-      PORT: "27015"
-      HLTV_PORT: "27020"
-      RCON_PASSWORD: "bro1337"
-      SV_LAN: "0"
-      VAC: "insecure"
+      MAP: "${START_MAP}"
+      MAXPLAYERS: "${MAX_PLAYERS}"
+      PORT: "${PORT}"
+      HLTV_PORT: "${HLTV_PORT}"
+      RCON_PASSWORD: "${RCON_PASSWORD}"
+      SV_LAN: "${SV_LAN}"
+      VAC: "${VAC}"