Allow for storing and loading Architectures as YAML

[Raahul-Singh]

Hey folks, I often use @ferrine's network builder to store my architectures as yaml files.
It is very convenient for complicated architectures and custom models.
You reckon we can introduce this here?
Probably store all the necessary config for a lightning module in a YAML and build the object through a factory class.

[ananthsub]

I strongly believe the Lightning framework should not require a configuration system for its use. The Python API is the most expressive.

That being said, if you find that system convenient to write your projects, feel free to use it! I believe the user should determine the config choice (if any) that works best for them

[Raahul-Singh]

Sounds fair!