Nit: use triple quotes for easier to read snippets

[dantasse]

In a file like https://github.com/lancedb/docs/blob/63a5de1c093374f4ddc3788333043c891d85e8ed/docs/snippets/geneva_dependency_verification.mdx, if we had """ or ''' blocks, we could still read the snippets. As it is, they're opaque here. Not critical bc the code is readable in the tests, but might be nice.