Add documentation comments

include/layers/input.cuh

@@ -5,11 +5,31 @@
 
 namespace Layers {
 
+/**
+ * @brief Input layer, just copies the input to the device
+ *
+ */
 class Input : public ILayer {
   public:
+    /**
+     * @brief Create a new Input layer
+     * 
+     * @param inputSize Size of the input vector
+     */
     Input(int inputSize);
+
+    /**
+     * @brief Destroy the Input layer
+     * 
+     */
     ~Input();
 
+    /**
+     * @brief Forward pass of the input layer. Just copies the input to the device
+     * 
+     * @param input Host pointer to the input vector
+     * @return Device pointer to the output vector
+     */
     float* forward(const float* input);
 
     void setWeights(const float* weights);