[Docs]add documentation to docsites

[MengqinShen]

Add documentation for Python Genkit for :

1. https://genkit.dev/docs/dotprompt/
2. https://genkit.dev/docs/agentic-patterns/
3. https://genkit.dev/docs/context/
4. https://genkit.dev/docs/model-context-protocol/
5. https://genkit.dev/docs/evaluation/