Using Armatures with Grease pencil object Are there any tutorial or help regarding using armatures with grease pencil object?

I found this video on Vimeo by Daniel M. Lara, its great but it does not explain how to go about with armatures.: https://vimeo.com/channels/greasepencil/173325517

There is a blend file available from the video on the cloud as well: https://cloud.blender.org/p/gallery/577ce46cc379cf0814b0ce50 

For someone who is new to the blender and from the 2d background, it would have been great if there was a detailed walkthrough available (at least for cloud subscriber).
Basically, every GP layer can be parented to a bone in the N properties panel. Each bone can control more than one layer, but every layer is controlled by a bone only, so you will have to create multiple layers. Use the "mantain volume" bone constraint to achieve "squash and stretch" effects.