Adding an "about Kantara" section

[hlflanagan]

In Section 3 "Terms and Definitions", line 111, the document refers to "Kantara's purposes." It might be helpful to the reader for this document to include a short paragraph that states what Kantara is and what its purposes might be. This should be part of the general boilerplate for Kantara specifications.

As an example, see https://www.ietf.org/id/draft-young-entity-category-05.txt section 1.1 - all documents produced by that organization (REFEDS) will have that paragraph in the spec.