Fix ImportError: Cannot import experiments from acme.jax

[natinew77-creator]

Summary

Fixes #335

The experiments submodule was not exposed in acme/jax/__init__.py, causing from acme.jax import experiments to fail with an ImportError when users install Acme via pip.

Problem

Users following the quickstart tutorial encounter this error:

from acme.jax import experiments
# ImportError: cannot import name 'experiments' from 'acme.jax'

Root Cause

The acme/jax/experiments/ submodule exists with a proper __init__.py that exports all necessary classes (ExperimentConfig, run_experiment, etc.). However, the parent module acme/jax/__init__.py was empty and didn't expose the experiments submodule.

Solution

Added the missing import statement to acme/jax/__init__.py:

"""JAX-specific components for Acme."""

# Expose the experiments submodule.
from acme.jax import experiments

Impact

This import pattern is used in:

• The quickstart tutorial (examples/quickstart.ipynb)
• All baseline example scripts (rl_continuous, rl_discrete, imitation)
• 21+ files throughout the codebase

Testing

• Verified syntax is valid with python3 -m py_compile
• The fix follows the same pattern used in acme/__init__.py for exposing submodules