Docs: Add a Search Feature in Docs

[niyabits]

Is your feature request related to a problem? Please describe.
I always want to find certain things in the documentation, and the docs have multiple pages and stitches API is something that I use it quite frequently in my application, I'd love to have a search feature.

Describe the solution you'd like
Add a search feature

• Optionally add ctrl+k as a shortcut to quickly go to the search.

Additional context
https://chakra-ui.com/ has a search and I love it.

I understand that the stitches has recently came out of beta and I don't have any sense of urgency for the feature, but I would love to see a search feature on the roadmap.

[niyabits]

Didn't realize that the website was in a different repo, and it already has an issue, so I am closing this issue.

stitchesjs/stitches-site#60