define xs and xxs configurations for shapenet

configs/shapenet_xs.yml

+name: shapenet_xs
+dataset: shapenet
+
+# training
+epochs: 100
+warmup_steps: 0.1
+batch_size: 1
+accumulate_grad_batches: 1
+
+learning_rate: 0.0003
+
+# architecture 
+embed_dim: 64
+num_heads: 4
+num_layers: 16
+num_positions: 4096
+num_vocab: 3
+tree_depth: 6
+spatial_dim: 3
+
+gpus: 8
+precision: 16

configs/shapenet_xxs.yml

+name: shapenet_xxs
+dataset: shapenet
+
+# training
+epochs: 30
+warmup_steps: 0.1
+batch_size: 4
+accumulate_grad_batches: 1
+
+learning_rate: 0.001
+
+# architecture 
+embed_dim: 16
+num_heads: 2
+num_layers: 8
+num_positions: 4096
+num_vocab: 3
+tree_depth: 6
+spatial_dim: 3
+
+gpus: 1
+precision: 16