NFS_LOG_LEVEL, not LOG_LEVEL

ehough · ehough · commit 09f299aedacc · 2019-03-08T13:57:05.000-08:00
diff --git a/doc/feature/logging.md b/doc/feature/logging.md
@@ -16,7 +16,7 @@ services:
     image: erichough/nfs-server
     ...
     environment:
-      - LOG_LEVEL: DEBUG
+      - NFS_LOG_LEVEL: DEBUG
 ```
    
 ### Normal log output
