Update tech-stack graphic & how it works copy

[Mornevanzyl]

• Update nox_tech-stack graphic with Nox.Project emphasis
• Include manual-entry option on graphic for service.yaml authoring
• Substitute en-dash with hyphens on all markdown docs
• Rewrite 'how it works' copy to move emphasis from service yaml file to project definition reflecting both service and entity yamls
• 'Slimmed' down default h1 font size and weight on markdown documents