Drools 8 doc port Commands chapter

• Drools commands
  https://docs.drools.org/latest/drools-docs/html_single/#_ch.commands

 
Commands are mainly targeted for the KIE Server but not only for that. For instance they are the preferred way to use a stateless session: you send a (batch of) command to it and then the session executes them and automatically dispose itself. I'd keep this in the docs removing all Kie Server related parts.