added JSON logging and updated readme

.env

@@ -1,10 +1,16 @@
-#GLOBAL
+#GLOBAL PATH VARIABLES
+
 APP_DATA_LOCATION=/path/to/docker_appdata
 APP_CONFIG_LOCATION=/path/to/docker_config
 LOGS_LOCATION=/path/to/docker_logs
+
+#ENVIRONMENT VARIABLES
+
 TZ=Europe/Paris
 HOST_USER_ID=1000
 HOST_USER_GID=1000
 PORT=20211
 
+#DEVELOPMENT VARIABLES
 
+DEV_LOCATION=/path/to/local/source/code