[Proposal] Use `great-docs` package for documentation

[adarshdigievo]

Motive

• We currently host our Python SDK documentation on Read the Docs.
• While Read the Docs is a great platform, it has limited support for self-hosting documentation pages and features such as copying a page as Markdown.
• Great Docs is a new open-source documentation site generator that better fits these needs.
• Using Great Docs, we can add doc generation to GitHub actions (command: great-docs setup-github-pages), and can host the SDK documentation at serpapi.github.io/serpapi-python
• Even though the library itself is newer (below 200 stars on GitHub), it is maintained by https://github.com/posit-dev, who already has a good portfolio of well-maintained Python packages.

Great-Docs package

• The generated docs are LLM-friendly by default. The package auto-generates a SKILL, llms.txt, and llms-full.txt for the documentation site.
• The package already has a lot of useful customization options (see https://posit-dev.github.io/great-docs/user-guide/introduction.html).
• Attaching a few screenshots from local testing: