docs: update Docs Product Specs

[0xHieu01]

Pages Docs Product Specs: https://jan.ai/docs/product/

Success Criteria Content that should be covered

• [ ] Docs Product Specs. Mostly for internal reference and for our core contributors who are building the SDK itself.
• [ ] Related keywords should be updated.
• [ ] Related images should be compressed.

Additional context Examples, reference pages, resources