Add a base autonomous class

The base autonomous class is useful for creating a nice template for `init` and `execute` instead of writing out the same code over and over.

Our base class should have
- An `init` method that returns `self` (this will resolve #12)
- An `execute` method that does nothing (this will be implemented by each Auto class that implements it)
- An `end` method that does nothing (this will be implemented by each Auto class that implements it)

Search the repository for existing Auto classes and the code related to issue #12 to identify the appropriate base-class entry point. Confirm how autonomous classes are initialized and executed, then verify that the new class provides init, execute, and end with the stated behavior without disrupting existing Auto classes.

Written by the indexing model from the issue text.