Update refreshmod docs.

This also affects pathmod here.

Since it's updating module-info.json, we could say that as well (this
should affect any tools which parse this file), but I haven't seen any
indication it's necessary in this context.

Bug: N/A
Test: N/A
Change-Id: Iecb6f454112b5c0095ee7063bc5442fdb1e3bd09