Rich text editor for pages

[camdendotlol]

Summary

• adds a pages/:uuid route for editing page contents
• update the Slate editor to use all the formatting options displayed in Figma
• adds an Insert dropdown to the Slate editor exclusively for the page form that allows the user to insert columns, events, and event comparisons
• updates API routes to reorder pages based on the parent page of a newly edited or created page

Screenshots