Edited makefile to run OS specific commands

Makefile

@@ -1,17 +1,28 @@
-buildfile = ./build/app
-
+# Variable definitions
 macOSFrameworks = -framework CoreVideo -framework IOKit -framework Cocoa -framework GLUT -framework OpenGL
 
+ifeq ($(OS), Windows_NT)
+	# Build for Windows:
+
+	# Not implemented yet
+else
+	# Build for MacOS or Linux:
+	buildfile = ./build/app
+	initCommand = mkdir -p build
+	compileCommand = clang++ -std=c++17 $(macOSFrameworks) -I ./include/ ./lib/libraylib.a ./src/main.cpp -o $(buildfile)
+	cleanCommand = rm $(buildfile)
+endif
+
 all: init compile run clean
 
 init:
-	mkdir -p build
+	$(initCommand)
 
 compile:
-	clang++ -std=c++17 $(macOSFrameworks) -I ./include/ ./lib/libraylib.a ./src/main.cpp -o $(buildfile)
+	$(compileCommand)
 
 run:
 	$(buildfile)
 
 clean:
-	rm $(buildfile)
+	$(cleanCommand)