Update to readme indicating instructions to develop the NG UI.

README.md

 # Building openBIS
 
 ## Requirements
-- JDK8 or JDK11
+- JDK11 or JDK 17
 
 ## Step By Step:
 ```
@@ -19,7 +19,7 @@ cd installation/
 They increase the time to obtain a build plus some tests could have additional environment requirements.
 
 ## Why the core UI made using GWT is not build anymore?
-It increases the time to obtain a build plus it requires JDK8, it will be removed on next release. For now it can be build following the next commands:
+It increases the time to obtain a build plus it requires JDK8, it will be removed on next release. For now it can be build following the next commands and only with JDK8:
 ```
 git clone https://sissource.ethz.ch/sispub/openbis.git
 cd openbis_standard_technologies/
@@ -59,3 +59,12 @@ openBISDevelopementEnvironmentDSSStart
 
 ## IntelliJ can't find package com.sun.*, but I can compile the project using the command line!
 Turn off "File | Settings | Build, Execution, Deployment | Compiler | Java Compiler | Use --release option for cross-compilation".
+
+# Developing openBIS NG UI
+- From the command line on the root folder of this repo:
+cd openbis_ng_ui
+npm install
+npm run dev
+
+- Open the path indicated on the command Line on the browser: http://0.0.0.0:8124/ng-ui-path/
+- The development mode of the openBIS NG UI requires to have openbis running