Github 404 Error when trying to access plugins examples

FoldingText current official release 2.2 (770).
Selecting “Software Development Kit” from the Help menu navigates to here:
file:///Applications/FoldingText.app/Contents/Resources/dist/sdk/docs/tutorial-Plugins.html

Near the bottom of this page there is an entry

  1. Learn from the existing plugins and use them as starting points for your own solutions.
    which links to this URL
    https://github.com/FoldingText/plugins/tree/FoldingText-Dev

That in turn generates a github 404 Error.