Add search functionality to the docs page

[ivpavici]

Is your feature request related to a problem? Please describe.
Let's try and integrate a search functionality into our docs page, for example: https://www.algolia.com/

[PhilippeR26]

See prototype : https://philipper26.github.io/starknet.js/

[PhilippeR26]

@ivpavici
Remember that we have to handle the right way the creation of the Algolia account (email + password).