Fix PyPI trusted publishing and publish the package

[ayhammouda]

Why

The README tells users to run uvx mcp-server-python-docs, but the package is not currently available on PyPI. That makes the public install path fail immediately, which blocks any serious star/launch push.

Evidence

• uvx mcp-server-python-docs --version fails with: package not found in registry.
• Release workflow for v0.1.1 failed in the Publish to PyPI job.
• Failure reason from GitHub Actions: invalid-publisher / no matching PyPI trusted publisher.
• Failing run: https://github.com/ayhammouda/python-docs-mcp-server/actions/runs/25066685238

Acceptance criteria

• PyPI trusted publisher is configured for this repository/workflow/environment.
• A new release publishes successfully to PyPI.
• uvx mcp-server-python-docs --version works from a clean environment.
• README install command is verified against the published package.