Add the missing title and text explaining how to use the playbook

[cmoulliard]

TODO

Add a title and text, part of the file, to explain how to use the playbook referenced as currently the link to the playbook is showed end of the file without any text to introduce it.

Note: The section VM required information should be better introduced too.

Question: Does it make sense to have 2 files; this one and the link to the ansible openstack doc file or only one ?

[cmoulliard]

Today, the documentation has been developed around 3 levels where level 1 is the README.adoc project file, 2nd level corresponds to a module that we support (kind, ibm-cloud, openstack, hetzner) and 3rd to files living close the place where we handle the code: playbooks, etc

WARNING: Some projects, like ibm-cloud do not follow this org as documentation and playbooks are maintained within the 2nd level ibm-cloud !

Questions:

1. Should we keep this documentation organisation and 3 levels or 2 levels ?
2. What about moving the playbooks within the project (kind, openstack, etc) as this is the case for ibm-cloud ?
3. If the answer to the question 2) is yes, should we also move the roles under the corresponding project too ? What about common roles ?
4. What should we do with the ./doc folder which contains *.md files ?

REMARK: If I remember correctly the idea/plan was using a tool to generate the role documentation. Correct ? Do we still use it ?

@jacobdotcosta