LeNet on MNIST + readme update (#12)

* LeNet on MNIST + readme update

* tanh + remove device toggle

* remove device entirely

Tools/mnist-tool/MNISTTool.swift

@@ -30,15 +30,11 @@ struct Train: AsyncParsableCommand {
     @Option(name: .long, help: "The PRNG seed")
     var seed: UInt64 = 0
 
-    @Option var layers = 2
-    @Option var hidden = 32
     @Option var batchSize = 256
     @Option var epochs = 20
     @Option var learningRate: Float = 1e-1
 
-    @Option var classes = 10
-
-    @Option var device = DeviceType.cpu
+    @Option var device = DeviceType.gpu
 
     @Flag var compile = false
 
@@ -62,9 +58,7 @@ struct Train: AsyncParsableCommand {
         let testLabels = data[.init(.test, .labels)]!
 
         // create the model
-        let model = MLP(
-            layers: layers, inputDimensions: trainImages.dim(-1), hiddenDimensions: hidden,
-            outputDimensions: classes)
+        let model = LeNet()
         eval(model.parameters())
 
         let lg = valueAndGrad(model: model, loss)

Tools/mnist-tool/README.md

@@ -1,8 +1,6 @@
 #  mnist-tool
 
-See other README:
-
-- [MNIST](../../Libraries/MNIST/README.md)
+See the [MNIST README.md](../../Libraries/MNIST/README.md).
 
 ### Building