adds a basic README

README.md

-# JupyterLab Base Image
+# JupyterLab for Java Base Image
 
-**Test it on** [![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/ebpro/notebook-qs-base/develop)
+**Test it on** [![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/ebpro/notebook-qs-java-base/develop)
 
-A base image for the Jupyter Lab ased on jupyter/minimal-notebook :
+A base image for Jupyter Lab for Java :
 
+* JDK 17 (Temurin) and Maven 3.8 from [sdkman](https://sdkman.io/)
+* Code Server Web IDE
+* PlantUML
 * ZSH
 * TexLive
-* Code Server Web IDE
 * Jupyter Book
+* Docker client
 
 ## Quickstart
 
+The notebooks and the working directories are separated in two directories (`/home/jovyan/notebooks/{notebooks,work}`) usually monted as volumes.
+
 ```bash
-docker run --rm --name jupyter-base-${PWD##*/} \
-  --volume data-${PWD##*/}:/home/jovyan/work/${PWD##*/} \
+docker run --rm --name jupyter-java-${PWD##*/} \
+  --volume data-notebooks-${PWD##*/}:/home/jovyan/notebooks \
+  --volume data-work-${PWD##*/}:/home/jovyan/work \
   --publish 8888:8888 \
   --env NB_UID=$UID \
-  brunoe/jupyter-base:develop start-notebook.sh --notebook-dir=work/${PWD##*/}
+  brunoe/jupyter-java-base:develop start-notebook.sh \
+      --notebook-dir=/home/jovyan/notebooks
 ```
 
 ## Host files and UIDs
 
+The image can be launched with two mounted directories :
+
+* one containing some notebooks.
+* another one for working files (caches likes maven local files `.m2`).
+
 ```bash
-docker run --rm --name jupyter-base-${PWD##*/} \
+docker run --rm --name jupyter-java-${PWD##*/} \
   --user root
-  --volume $PWD:/home/jovyan/work/${PWD##*/} \
-  --volume /var/run/docker.sock:/var/run/docker.sock \
+  --volume $PWD:/home/jovyan/notebooks \
+  --volume $HOME/JUPYTER_WORK:/home/jovyan/work \
   --publish 8888:8888 \
   --env NB_UID=$UID \
-  brunoe/jupyter-base:develop start-notebook.sh --notebook-dir=work/${PWD##*/}
+  brunoe/jupyter-java-base:develop start-notebook.sh \
+      --notebook-dir=/home/jovyan/notebooks
 ```
 
 ## With Docker support
 
+The image includes `docker client, compose and buildx`. 
+It supports mount docker socket.
+
 ```bash
-docker run --rm --name jupyter-base-${PWD##*/} \
+docker run --rm --name jupyter-java-${PWD##*/} \
   --user root \
   --privileged=true \
   --volume $PWD:/home/jovyan/work/${PWD##*/} \
   --volume /var/run/docker.sock:/var/run/docker.sock \
   --publish 8888:8888 \
   --env NB_UID=$UID \
-  brunoe/jupyter-base:develop start-notebook.sh --notebook-dir=work/${PWD##*/}
+  brunoe/jupyter-java-base:develop start-notebook.sh \
+      --notebook-dir=/home/jovyan/notebooks
 ```