Markerting video and tutorials

Marketing video:

• ice cream intro (needs to be shortened)
• max length 1:30-2:00
• show parse area, canvas input with some text as of their function (15-20 secs each)
• outro ice-cream

Tutorial videos

TBD, some quick points:

• at least in Red and ABNF
• examples should build on each other in complexity
• one "final grammar" which we build out in tutorials. Suggestion: address
• also tutorials on using DG itself. We'll need to make a list for that.