Fix target all and correct raylib path in Makefile

Startcode/makefile

@@ -1,5 +1,8 @@
 CC = gcc
 CFLAGS = -g -Wall
+mnist: main.o matrix.o neuralNetwork.o imageInput.o mnistVisualization.o ./windows/libmnist_complete.a ./windows/libraylib.a
+	gcc -o mnist main.o matrix.o neuralNetwork.o imageInput.o mnistVisualization.o ./windows/libmnist_complete.a ./windows/libraylib.a -lopengl32 -lgdi32 -lwinmm
+
 
 ifeq ($(OS),Windows_NT)
 	include makefile_windows.variables