Slice 1: Add Rich Text Editor Widget

[mnholtz]

Implementation sketch

See https://www.notion.so/pixiebrix/Phase-1-Implement-Rich-Text-Editor-f74aea6b845847c0ad25f81d8236da3c?pvs=4#12643b21a25381df9c1ac8f16e1897c4

Acceptance Criteria

Rich-Text Field Available in Form Builder bricks

• Given a user is configuring a “Show Modal or Sidebar Form” or “Custom Form” brick
• When ‘input type’ is selected
• Then one of the options should be “Rich Text Editor”

Rich-Text Field in Form Preview

• Given a user is configuring a “Show Modal or Sidebar Form” or “Custom Form” brick
• When a “Rich Text Editor” field is added or edited
• Then the Form Preview should display a preview of the editor

Rich-Text Field Outputs HTML

• Given a modal or sidebar form with a “Rich Text Editor” field
• When the form is submitted
• Then the output value for the field should be in HTML format