updated build instructions

misc/MoreUsage.md

@@ -28,18 +28,20 @@ you can build the app yourself like this:
 go build -o password-generator ./
 ```
 
+NOTE: If you build the app manually in go, like shown in this example, it will probably not run, since it misses a writeable `/data` directory.
 
 
 # build a docker container
 
 ```
-docker build -t password-generator .
+docker build -t web-password:dev .
+
 ```
 
 # start the docker container
 
 ```
-docker run -p 8080:8080 password-generator
+docker run -p 8080:8080 -v app_data:/data web-password:dev
 ```
 
 ## docker-compose