chore: import upstream snapshot with attribution

modules/pe/rmvpe/seq.py

@@ -0,0 +1,10 @@
+import torch.nn as nn
+
+
+class BiGRU(nn.Module):
+    def __init__(self, input_features, hidden_features, num_layers):
+        super(BiGRU, self).__init__()
+        self.gru = nn.GRU(input_features, hidden_features, num_layers=num_layers, batch_first=True, bidirectional=True)
+
+    def forward(self, x):
+        return self.gru(x)[0]