* Docs: Configurator Support
* Minor updates
* Updated keyboard.h example to use #pragma once
per @drashnahttps://github.com/qmk/qmk_firmware/pull/4396#discussion_r232140934
* Add link to doc under Reference section
Added to _sidebar.md and _summary.md
* Changed doc title; minor tweaks
Re-titled the doc as "Supporting Your Keyboard in QMK Configurator".
Made some minor changes to the keyboard.h examples.
* Added tags object to JSON example