Add Pages and Reorgainze Examples for Learning Processing

[duskvirkus]

Came out of #1976

Most of the Learning Processing videos currently on the website aren't linked to or are missing code. If you can find the correct code in processing examples and match it to an existing page that would be great.

If we could also add pages for sessions 9 and up that would be great. Also looks like there maybe missing videos in existing sessions.

Here are playlists for some of those sessions:

• 9: https://www.youtube.com/playlist?list=PLRqwX-V7Uu6bO9RKxHObluh-aPgrrvb4a
• 10: https://www.youtube.com/playlist?list=PLRqwX-V7Uu6YB9x6f23CBftiyx0u_5sO9
• 11: https://www.youtube.com/playlist?list=PLRqwX-V7Uu6bw0bVn4M63p8TMJf3OhGy8

Right now the pages are under _Courses/learning-processing and the code is under Tutorials/Processing which might be confusing. We plan to restructure eventually you can read more about that here #1750.

I'll probably work on this slowly over the next few weeks but would appreciate any help. Feel free to ask any questions. Would prefer to keep pull requests on the smaller size to make it easy to merge them, so probably one video at time. Also it's helpful if you comment here and say you're working on something so two people don't do the same thing.