Updated the Getting Started guide (#81)

* Rewrote the Getting Started guide to include operator and service deployment.

* Updates to quickstart document

* Updates to quickstart document and links added to the main documentation page.

* Fixed a typo

* Updated quickstart guide diagrams. Renamed references to orchestrator as controller node.

* Minor edits

* Update modules/ROOT/pages/getting_started.adoc

Co-authored-by: Sönke Liebau <soenke.liebau@stackable.de>

* Update modules/ROOT/pages/getting_started.adoc

Co-authored-by: Sönke Liebau <soenke.liebau@stackable.de>

* Update modules/ROOT/pages/getting_started.adoc

Co-authored-by: Sönke Liebau <soenke.liebau@stackable.de>

* Update index.adoc

Co-authored-by: Sönke Liebau <soenke.liebau@stackable.de>

Author: Jimvin