Updating pages with improved documentation

[wendellpiez]

More resources including architecture diagram; links to wiki; many editorial improvements.

• Adding some top-level docs including testing plan and pub checklist
• Adding system architecture diagram; more edits
• renamed: system-architecture-diagram.svg -> docs/system-architecture-diagram.svg
• More edits now with links to wiki?
• Moving resources; directory edit; more docs
• Repairing broken image link?
• Learning how to link to wiki, maybe
• Slight adjustments to architecture diagram
• recasting aspect ratio of system architecture diagram, with other improvements
• More finer adjustments to diagram
• Tiny Y adjustment on label in diagram
• Further visual enhancements on architecture diagram
• Further tweaks to diagram
• Further incremental improvements
• More readme touchups
• Adding path representing XSLT parameterization to system diagram
• Further touchups (some copy being moved to wiki)
• More touchups addressing feedback.
• Further touchups and corrections.
• Trying to code up links for Github