Docs: additional Quickstart clarification and improvements

[odilitime]

Relates to:

#298

Risks

Low to none

Background

What does this PR do?

Improve quickstart:

• break up step by step command into individual blocks so copy&paste functions integrates easier with user's needs
• improves some visual formatting in source and render
• improves accuracy of character section, including being explicit which character when starting to reduce confusion
• also clarify common issues and add a bit more help to last item

What kind of change is this?

Documentation update

Documentation changes needed?

no, it is a doc change