[Docs] Update docs to reflect OCP Change structure of provided install & example files

Current structure of installation is very basic and not very user friendly.

Make structure nicer, easier to use and plausible to end-user.

Don't scare new users by showing all files at ocp-install-examples.zip file.

initial PR https://github.com/artemiscloud/activemq-artemis-operator/pull/360/

Suggested conventions to use from now on (on all provided examples and install files):

• use only underscores in files (don't mix dashes/minuses and underscores)
• Update README.md with more suitable wording
  • backreference upstream project or get rid of completely make generate-deploy goal
• Unify CR/CRD naming structure
• Simplify installation and instructions (ideally just change namespace and decide on namespace/cluster-wide operator deployment)