Document kayenta customInlineTemplate and customFilterTemplate properties for each CanaryMetricSetQueryConfig

Issue Summary:

customInlineTemplate and customFilterTemplate properties seem to be mostly undocumented, with no instructions on how to use them, and are not included in https://github.com/spinnaker/kayenta/blob/master/docs/canary-config.md

Cloud Provider(s):

Kubernetes

Environment:

Feature Area:

Description:

Steps to Reproduce:

Additional Details:

kayenta repo does not allow Issue reports - and there is no obvious place to do so listed in the README.