Fix indent

Author: mikebo93

chapter_programming_model/Neural_Network_Programming.md

@@ -81,21 +81,21 @@ and `torch.nn.Module` in PyTorch. Code
 **ch02/code2.3.2**
 ```python
 class MLP(nn.Module):
-def __init__(self, input_size, hidden_size, num_classes, dropout_rate=0.5):
-    super(MLP, self).__init__()
-    self.fc1 = nn.Linear(input_size, hidden_size)
-    self.bn1 = nn.BatchNorm1d(hidden_size)
-    self.relu = nn.ReLU()
-    self.dropout = nn.Dropout(dropout_rate)
-    self.fc2 = nn.Linear(hidden_size, num_classes)
-
-def forward(self, x):
-    out = self.fc1(x)
-    out = self.bn1(out)
-    out = self.relu(out)
-    out = self.dropout(out)
-    out = self.fc2(out)
-    return out
+    def __init__(self, input_size, hidden_size, num_classes, dropout_rate=0.5):
+        super(MLP, self).__init__()
+        self.fc1 = nn.Linear(input_size, hidden_size)
+        self.bn1 = nn.BatchNorm1d(hidden_size)
+        self.relu = nn.ReLU()
+        self.dropout = nn.Dropout(dropout_rate)
+        self.fc2 = nn.Linear(hidden_size, num_classes)
+
+    def forward(self, x):
+        out = self.fc1(x)
+        out = self.bn1(out)
+        out = self.relu(out)
+        out = self.dropout(out)
+        out = self.fc2(out)
+        return out
 ```
 
 Figure :numref:`ch03/model_build` demonstrates the intricate process of