Fix "and needs further work."

[koppor]

CSD06:

Note that relationship template grammar is underspecified currently and needs further work.

Proposal: Remove that sentence.

[pmjordan]

Having heard this issue discussed at the ad hoc working group meeting I suggest the sentence is replaced by something like:
'While relationship templates can be useful in certain modelling situations, they are not the logical equivalent of node templates and in the future may be renamed to reflect this.'