Refactor datasets into LeRobotDataset (#91)

Co-authored-by: Alexander Soare <alexander.soare159@gmail.com>

lerobot/configs/env/aloha.yaml

@@ -10,7 +10,8 @@ online_steps: 25000
 
 fps: 50
 
-dataset_id: aloha_sim_insertion_human
+dataset:
+  repo_id: lerobot/aloha_sim_insertion_human
 
 env:
   name: aloha

lerobot/configs/env/pusht.yaml

@@ -10,7 +10,8 @@ online_steps: 25000
 
 fps: 10
 
-dataset_id: pusht
+dataset:
+  repo_id: lerobot/pusht
 
 env:
   name: pusht

lerobot/configs/env/xarm.yaml

@@ -9,7 +9,8 @@ online_steps: 25000
 
 fps: 15
 
-dataset_id: xarm_lift_medium
+dataset:
+  repo_id: lerobot/xarm_lift_medium
 
 env:
   name: xarm