Improve beginner experience with courses

[Hennzau]

Objective

Hi all! This PR adds some courses (and other fun stuff) to improve the beginner experience. :)

Courses

I added them under courses/ for now. Here’s why I thought they might be useful:

• No. 1: A getting-started course with a really simple dataflow and project structure (talker/listener).
• No. 2: Make the app from the previous tutorial a bit more dynamic using dynamic nodes.
• No. 3: Make a local terminal chat app.
• No. 4: Improve your last app with deployed dataflows.
• No. 5: Use our node hub to display text on your screen.
• No. 6: ?

Bugs we need to solve

• Dynamic dataflows can not be stopped on Linux and MacOS for 0.3.6 #647
• coordinator crashes on bad logs access #648