This is a docs change in support of Change-Id:
Dispatchers now only record meter or event data and are configured
independently. The install guide is updated to reflect this
distinction. Because the referenced Change-Id used Doc-Impact
as a flag instead of the non-hyphenated variant there is no
independant bug in the OpenStack Manuals project for this change.
Additionally, existing content for configuring Gnocchi is broken out
into more detail.