build: create Makefile with cross-platform targets

Makefile

@@ -0,0 +1,37 @@
+CC = gcc
+CFLAGS = -Wall -Wextra -Iinclude
+LDFLAGS = -lraylib -lopengl32 -lgdi32 -lwinmm
+
+SRC = src/main.c src/chip8.c
+OBJ = $(SRC:.c=.o)
+TARGET_DIR = .bin
+TARGET = $(TARGET_DIR)/chip.exe
+
+# OS and shell command detection
+ifeq ($(OS),Windows_NT)
+    MKDIR = if not exist $(TARGET_DIR) mkdir $(TARGET_DIR)
+    CLOSE_CHIP = taskkill /f /im chip.exe 2>NUL || exit 0
+    CLEAN_CMD = if exist src\main.o del /f src\main.o & if exist src\chip8.o del /f src\chip8.o & if exist $(TARGET_DIR) rmdir /s /q $(TARGET_DIR)
+else
+    MKDIR = mkdir -p $(TARGET_DIR)
+    CLOSE_CHIP = killall chip 2>/dev/null || true
+    CLEAN_CMD = rm -f src/*.o && rm -rf $(TARGET_DIR)
+endif
+
+all: $(TARGET)
+
+$(TARGET): $(OBJ)
+	@$(CLOSE_CHIP)
+	@$(MKDIR)
+	$(CC) $(OBJ) -o $(TARGET) $(LDFLAGS)
+
+%.o: %.c
+	$(CC) $(CFLAGS) -c $< -o $@
+
+clean:
+	@$(CLEAN_CMD)
+
+run: all
+	@$(TARGET) $(ROM)
+
+.PHONY: all clean run