Simplify and improve the readme

[Valve]

1. Have correct and context-aware doc links available by every code example (use entity and section deep-linking for that).
2. Supported stuff table should be more interesting. Put the stuff that's the hardest first
3. Make cloud integrations a separate document and just link to that from the readme. The cloud intnegrations doc should explain briefly what's posisble and then link to the actual botd-integrations project.
4. Simplify as much as possible, use simple English