Improve "Installation" section

[amotl]

I like how the Context7 MCP Server presents the many different variants of installations into relevant applications and frameworks. Thanks for referring to that, @surister.

Let's implement this directly on the documentation page for the CrateDB MCP Server instead of on its README?

-- https://cratedb.com/docs/guide/connect/mcp/cratedb-mcp.html

[amotl]

In recent release notes about FastMCP 3.0 or 3.1, the authors mentioned the new fastmcp install subcommand that can install MCP servers into Claude and other environments fluently.