refactor documentation to remove react-desc

We can have issues in our documentation due to react-desc trying to combine propTypes with documentation and not always working well on either side. For example, we cannot reference propTypes from react-desc in other components due to how they are decorated. And, we need the ability to provide richer example syntaxes that don’t work with the more simplified propType derived approach.

A suggestion is to have two files per component: propTypes.js and doc.js. The former would just have the propTypes and could be reference from other components. The latter would change the current documentation by removing the programatic prop definitions and instead support a richer syntaxExamples per each property, similar to what we do in grommet-site. The README.md files per component would be generated from doc.js with better syntax examples that aligned with grommet-site.

[ericsoderberghp]

Two years later …

• I think we should remove react-desc entirely.
• I think we should out the propTypes in a separate file, that makes the typescript typings and prop types consistent. I suggest this because I think there is enough complexity in some of the components typings that adding them into the component file would make it a bit unwieldy.
• I think all of the documentation should be in moved to the grommet-site repository. This will allow more customization of how complex types are described but just describing them in markup, rather than building a more complex JSON structure just to then have to convert that to markup later.
• I think we should update grommet-site to show properties with different types where there are different descriptions and examples for each type, rather than trying to merge those into a single description.
• I think we should simplify the README files to just contain a link to the appropriate documentation page.

[ericsoderberghp]

Superceded by #5353