docs: add Parallel Search MCP setup

[georgeatparallel]

What this PR does / why we need it?

Adds an English and Chinese setup example for public web search and page extraction through MaxKB’s existing MCP tools. It gives users a working Streamable HTTP configuration that needs no Parallel account or API key.

Summary of your change

The READMEs cover creating the MCP tool, selecting it in an agent, and removing the connection. They explain rate limits and which queries, URLs, and context go to Parallel when the agent calls the tools. The example sends User-Agent: MaxKB so Parallel can measure aggregate free MCP usage. No runtime code, defaults, or existing connections change.

Validated the exact JSON from both READMEs using MaxKB’s unchanged validate_mcp_config and _initialize_skills functions in isolation, with its pinned MCP client dependencies. Live discovery, web_search, and web_fetch succeeded without credentials; outbound request capture confirmed the header on both tool calls. git diff --check passes. The full browser/database flow and downstream analytics were not tested.

I work at Parallel, which operates this service.

Please indicate you've done the following:

• Made sure tests are passing and test coverage is added if needed. Focused client checks above; no runtime changes or new regression tests.
• Made sure commit message follow the rule of Conventional Commits specification.
• Considered the docs impact and opened a new docs issue or PR with docs changes if needed. This PR updates both READMEs.