Consider renaming groot directory/module to gr00t

From PR #56 review (item #49).

NVIDIA brands it as `gr00t` but Python identifiers can't start with digits or contain `00` in module names. Currently using `groot` which is the standard Python convention.

Options:
1. Keep `groot` (current, Pythonic)
2. Rename to `gr00t` package with `__init__` alias
3. Add `gr00t` as an importable alias

**Priority**: Low — naming/bikeshed