Add .md pages describing how to test (with real hardware)

Per Kamakura planning meeting (Nov 21), each device service should provide a HOWTOTEST.md page that describe how to check the base functionality of the device service with real hardware. These tests should be run manually before each release.

Each device service should also provide a WORKSWITH.md page that lists the actual hardware (make, model, web site link, etc.) that the device service has been tested with and known to work with. Provide enough details on the device/sensor so that an adopter would know where to go to get the same device.

The SDK should provide templates for these files.

Start by identifying each device service and the SDK location where shared documentation templates belong. Add HOWTOTEST.md and WORKSWITH.md guidance for every service, including manual real-hardware checks and tested device details; completion means the SDK provides both templates and each service documents its supported hardware and release checks.

Written by the indexing model from the issue text.