Design Guide document URI updated

Hi all,

FYI, the Design Guide document changed the URI from ( 
https://w3c.github.io/coga/requirements/ ) to ( 
https://w3c.github.io/coga/design/ ).

Now the Design Guide document URI is https://w3c.github.io/coga/design/

Those related links to this document have been updated.

Thank you and Best Regards,

Roy