Add a "type" to the mongo-express code block

mongo-express/content.md

@@ -52,7 +52,8 @@ The following are only needed if `ME_CONFIG_MONGODB_ENABLE_ADMIN` is **"false"**
 
 ## Example
 
-	docker run -it --rm \
+```console
+$ docker run -it --rm \
     --name mongo-express \
     --link web_db_1:mongo \
     -p 8081:8081 \
@@ -60,5 +61,6 @@ The following are only needed if `ME_CONFIG_MONGODB_ENABLE_ADMIN` is **"false"**
     -e ME_CONFIG_BASICAUTH_USERNAME="user" \
     -e ME_CONFIG_BASICAUTH_PASSWORD="fairly long password" \
     mongo-express
+```
 
 This example links to a container name typical of `docker-compose`, changes the editor's color theme, and enables basic authentication.