New editors draft of RPDE specification

Hi,

I've created a new editors draft of the RPDE specification, I've started
making some revisions there that will become version 1.1 of that document.

The working document is at:

https://www.openactive.io/realtime-paged-data-exchange/EditorsDraft/

The changes are minor to ensure backwards compatibiliy. They lay the
ground-work for better feed validation and support for facilities.

There are now three optional properties for feeds which indicate version
number of specifications in use, and the types of entity included in a
feed. Details can be found in the table here:

https://www.openactive.io/realtime-paged-data-exchange/EditorsDraft/#response-grammar

I would also like to tidy up the specification in this release to make the
use of the standard data model more prominent. I've filed an issue here if
anyone has thoughts:

https://github.com/openactive/realtime-paged-data-exchange/issues/84

Cheers,

L.

-- 
Leigh Dodds, Data Infrastructure Programme Lead, theodi.org
@ldodds
The ODI, 65 Clifton Street, London EC2A 4JE