More detailed instructions

[jperedadnr]

Since #1 is pending, to test this archetype you need to download or clone this repo, and you'll need to build and install first the artifact locally.

The instructions should say:

1. Install the archetype: Clone or download the repository, (select Java 9/11?) and run:

mvn install

2. Create the project (outside the archetype project!)
   ...

3. Run

...