Next version of the ICD.

Here are some addings and improvements already identified : 

TitleDescriptionRef in document
Mission specific requirements 

Comment from Jolyon in version 1.1:

Which would only be needed if we have to add extra queriables for a particular mission?  Otherwise mission class specific json elements should be directly imported from the EOPF STAC metadata?  It could be useful to clarify this in a next version.

2.2

Export PRIP CatalogueFunction to be specified2.2
On demand ProcessingFunction to be specified2.2