How do I create a new Content Block in Design Studio?

It should be noted that I would not be asking this question IF:

1. There existed information in the Courses section on creating & modifying content blocks

2. I could find something related to creating & configuring content blocks, when I search "content block" in the "ask a question" search bar.

Since there is either no information published on creating & modifying content blocks, or such information is hidden in obscurity,

I ask my question:

How do I create a new Content Block in Design Studio?


And I issue recommendations to Marketo:

1.  Include information on creating content blocks within your Email Program tutorial video.  Not including information on how to set up and configure content blocks is a huge fail.