Add examples

[alisomay]

I'd like to add multiple examples in an examples folder for people to start fast and easy.

Some ideas are,

• Sine (hello world) ✅
• Messaging with pd ✅
• Writing and reading from arrays
• Usage of some less commonly used functions
• Embedding to nannou ✅
• Embedding to Bevy
• Examples with specifically with cpal
• Examples with other cross platform audio libraries.

I'd like most of the examples to contain nice music.
Also I would like that all of them to produce audio.