decentralize spec by adding docs to individual repos and combine/aggregate them hyper modular into spec docs

[serapath]

@todo

• [ ] distribute docs among all existing repos where they belong
• [ ] fetch and show on a docs landing page
• [ ] write JS API DOCS
  • include code snippets in markdown document
  • Attach SUBSTRATE/POLKADOT API source files to SEQUENCE DIAGRAM
  • Use ctrl+ to make it bigger :) for SEQUENCE DIAGRAM and maybe screenshot it for github

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