explicitly address updating or editing an I-D

[ghwood]

AFAICT, the authors.ietf.org site does not directly speak to how an author can update an I-D submitted to the IETF I-D repository, or that submitting a new version to the repository is effectively the way one "edits" an already-submitted I-D.

There are a number of ways this gap might be addressed. For example, there could be additions/updates to existing text, for example at the Submitting your Internet-Draft page. However, it might be clearer to have a new page/entry under "Key Processes" called "Updating and editing an I-D".