twiki page for TAP registry extension development

[Ray Plante]

Mireille, Pat, and Keith,

To jump start the development of a TAP registry extension, I've created a 
TWiki page called TAPRegExt 
(http://www.ivoa.net/cgi-bin/twiki/bin/view/IVOA/TAPRegExt).  This is a 
place to start collecting the concepts we want to capture in a TAP 
registry record.

I've also included some pointers to information about how to create a 
registry extension.

cheers,
Ray