Movable Refactor Update
- Simplified Movable class to only account for one dimension,
  renamed to Movable1D. This reduces duplicate code and allows for
  easy extension into contexts with varying dimensions. Objects
  with directions in two dimensions will be composed of two Movable
  objects.
- Movable should still be encapsulated behind an interface.
Movable1D Description Update
- Updated description for Movable1D.
Fixed git merge conflicts.