Make videos that present the different modules, core classes, concepts, etc.

[asogaard]

Suggested steps:

• [ ] Use existing written tutorial(s) as baseline
• [ ] Prepare content plan for various tutorial videos
• [ ] Find place to host videos
• [ ] Create videos
• [ ] Publish videos

Examples:

• https://www.pytorchlightning.ai/tutorials

Related to #401, #537