Review Estuary's Docusaurus and other documentation sites to see how ours can be improved

[APiligrim]

Figma doc: https://www.figma.com/file/h6ucDlKHw67QfNvYM6jLjG/Estuary-Ecosystem?node-id=90%3A26&t=L3DJXvHoi6Eak6tD-1

Phil will be assigning issues for next steps