update README.md

Author: HurinHu

.gitignore

@@ -7,3 +7,5 @@
 .Trashes
 ehthumbs.db
 Thumbs.db
+
+build

README.md

@@ -1,13 +1,8 @@
 # jupyter-docker
 
-## Config
+## Build and run
 set external dir as workspace in `build` file by replace `<your path>` to your workspace path
 ```
+docker build -t jupyter .
 docker run --name jupyter --restart=always --network=host -p 8888:8888 -v <your path>:/home/jupyter jupyter
 ```
-
-## Build and run
-you can change docker run args in `build` file line 5
-```
-./build
-```