We'll need a websocket to communicate with Create Workspace form. On each form input change, the websocket will use https://github.com/coder/preview to re-render the parameter options and then communicate the new parameters back to the frontend.

The communication types for the websocket ideally live in the preview repo so that project can continue to have a local demo environment with the same types as production.

The websocket needs to accept the below as inputs, as they are used to render the current set of parameters:

• terraform plan json output
• Coder user context (Coder workspace owner context, load in all fields preview#46)
• template tar file
• user form inputs