Add DocSearch feature to Yorkie documentation

[devleejb]

Description:

Currently, the Yorkie documentation lacks a search feature, which hinders user navigation and information retrieval. One possible solution is to integrate DocSearch, a tool that provides search functionality for documentation websites.

DocSearch operates by crawling web pages at regular intervals and creating a searchable index based on the content it finds. It is currently available for free and can significantly improve the user experience of the Yorkie documentation by enabling users to search for specific topics or keywords.

Why:
Adding the DocSearch feature to the Yorkie documentation will enhance usability and make it easier for users to find relevant information quickly. By implementing this feature, we can improve the overall accessibility and navigability of the documentation.

Additional Information:
For more details on how DocSearch works and how to apply for the service, please refer to DocSearch official page.