[skip ci]remove useless comments form docker build doc (#9383)

Signed-off-by: NWeida Zhu <weida.zhu@zilliz.com>

build/README.md

@@ -79,7 +79,7 @@ You can also get into the dev containers for development.
 Enter root path of Milvus project on your host machine, execute the following commands:
 
 ```shell
-$ ./scripts/devcontainer.sh up        # start Dev container
+$ ./scripts/devcontainer.sh up
 
 Creating network "milvus-dev" with the default driver
 Creating milvus_jaeger_1  ... done