Add support for embeddings for similarity search or llm use.

[wbste]

As the number of bookmarks grow it's increasing hard to pick the right keyword to use for search and to find what one is looking for. It would be great if we could add embeddings to the context of the bookmark that uses the title or body text to create embeddings, then perform similarity search. Other projects exist like https://github.com/asg017/sqlite-lembed and https://github.com/asg017/sqlite-vec that may be able to speed up this process.