As a developer I always want existing content to be rendered in a page, even if the frontend component has not been built yet.

As an author I would like to start entering content and seeing content, even if the developers have not yet provisioned the frontend component.

Notes: 

Supply a simple default fallback component in each of the frontend helper libraries that renders all of the root props it recieves (but not the metadata).

This would be helpful during development - that the page just renders something even if I have not created a frontend component yet. It would also be useful when I make a mistake - such as not supplying the proper mapping configuration, or forgetting it, or making a TYPO - then at least I see that the content is indeed there.

Rendering should be simple, for example.

Template not found: my-light-module:/templates/components/booook 

name: Gone with the wind.
pages: 556
description: Some kind of description about the thing I don't know what exactly.
ISBN: 4848493938383
category: [category uuid]

In addition to the default fallback compoent, allow a developer to optionally provide their own fallback component.  Which one to use could be included in the 'config' object which is passed to EditablePage .

const config = {  
  componentMappings: {    
    'nextjs-ssr-minimal-lm:pages/basic': Basic,    
    'spa-lm:components/headline': Headline,    
    'spa-lm:components/image': Image,     
  },

  fallbackComponent: MyFallbackComp,

};

AC:

• Only is used during development or when authoring. Should not be displayed in production/published context. In that case nothing should be rendered.
• Only is used when Authoring in PageEditor, when not in page editor then no fallback is rendered.
• In the default component, only render root nodes, not subnodes - to prevent too much content from being rendered.