Starting on the model.h, but need to make layer structs and structs for loss and optimizers

include/modules/neural_networks/activation_functions/Activation_Sigmoid.h

@@ -4,6 +4,7 @@
 
 #include "utils/vector.h"
 #include "utils/matrix.h"
+#include "modules/neural_networks/layers/Layer.h"
 
 #include "numerics/neg.h"
 #include "numerics/exp.h"
@@ -15,7 +16,7 @@
 namespace neural_networks{
 
 	template <typename T>
-	struct Activation_Sigmoid{
+	struct Activation_Sigmoid : Layer<T>{
 
 		utils::Matrix<T> _inputs;
 		utils::Matrix<T> outputs;