JAMES-3663 Update James webadmin-cli documentation

[quantranhong1999]

Hello dear Hocktoberfest, and thanks for considering helping us!

The goal of this issue is to contribute to https://github.com/apache/james-project (yes, an Apache project!) but for technical reasons, we could not open tickets on that repository...

You can gather a bit more information on what is James and why it's an awesome project on our website.

Here are the more specific task details:
Link to JIRA: https://issues.apache.org/jira/projects/JAMES/issues/JAMES-3663

Before receiving further command groups contributions, James Webadmin CLI README.md is not up-to-date now because of some contributions back then without updating it.

We need to update it! It is likely we need to update README.md about the global quota group command and some additional domain commands(add domain alias, list domain alias, remove domain alias)...

If you do have any questions, just discuss it here or reach us on Gitter: https://gitter.im/apache/james-project

[chibenwa]

James Webadmin CLI README.md link ?

[quantranhong1999]

James Webadmin CLI README.md link ?

Ok I added it.