add modules dir to init

Author: ahalev

src/pymgrid/__init__.py

@@ -10,12 +10,14 @@
 from .utils import add_pymgrid_yaml_representers, dry_run
 
 import pymgrid.envs
+import pymgrid.modules
 
 __all__ = [
     'add_pymgrid_yaml_representers',
     'dry_run',
     'Microgrid',
     'MicrogridGenerator',
     'NonModularMicrogrid',
-    'envs'
+    'envs',
+    'modules'
 ]