Add ChonkBook

[bhavnicksm]

This pull request includes significant updates to the cookbook/README.md file to enhance its content and structure. The most important changes include the addition of new sections for official tutorials, community integrations, community blogs and resources, and contributing guidelines.

Enhancements to cookbook/README.md:

• Added a centered header with the Chonkie Cookbook logo and title.
• Introduced a section for official tutorials, including a table with a tutorial on recursive chunking for PDF/Markdown documents.
• Added a section for community integrations, featuring projects like FlashRAG and txtai, and instructions for adding new integrations.
• Created a section for community blogs and resources, listing various types of content such as videos and blog posts related to Chonkie.
• Included a contributing section with a link to the contribution guidelines and information on how to add projects or integrations to the cookbook.