Update @daffodil/design core directive docs

[xelaint]

📄 Documentation Request

What were you doing?

From a component API doc that uses DaffColorableDirective as a hostDirective, I don't know what options are available to me from DaffPalette unless I navigate to the DaffPalette page.

Expected behavior

The input doc of each directive should list out the available options.

i.e.

In DaffColorableDirective:

 /**
   * Sets the color on a component.
   * 
   * `
   */
  @Input() color: DaffPalette;

should be:

 /**
   * Sets the color on a component.
   * 
   * `'primary' | 'secondary' | 'tertiary' | 'light' | 'dark' | 'theme' | 'theme-contrast' | 'black' | 'white'`
   */
  @Input() color: DaffPalette;

Existing Documentation

Environment

Daffodil version: X.Y.Z
Angular version: X.Y.Z 

 
For Tooling issues:
- Node version: XX  
- Platform:  

Others:

[xelaint]

Reopened. Missing docs for:

• Skeleton
• Compact
• Open