Consistent naming in docs and examples.

[coledie]

Currently there is no standard variable / class naming scheme for all the examples and usage docstrings. This will cause confusion for people trying to copy pieces of code to use and understand from.

** Only include essential fixes. **

• Callback and TrainingLoop both use name experiment often, make only TL use it, and use it everywhere. Callback always named callback.
• Rename network._template_parts to just parts or something dang