implement Makefile and CPU module with reset and state print functions; update .gitignore to exclude build artifacts

Makefile

@@ -0,0 +1,32 @@
+cc := gcc
+CFLAGS := -std=c11 -Wall -Wextra -Wpedantic -O2
+CFLAGS_DEBUG := -std=c11 -Wall -Wextra -Wpedantic -g -O0
+
+SRC_DIR := src 
+BUILD_DIR := build 
+BIN_DIR := bin
+
+TARGET := $(BIN_DIR)/mos6502
+
+SRC := $(shell find  $(SRC_DIR) -name '*.c')
+OBJ := $(SRC:$(SRC_DIR)/%.c=$(BUILD_DIR)/%.o)
+
+all: $(TARGET)
+
+$(TARGET): $(OBJ)
+	@mkdir -p $(BIN_DIR)
+	$(cc) $(OBJ) -o $(TARGET)
+
+$(BUILD_DIR)/%.o: $(SRC_DIR)/%.c
+	@mkdir -p $(BUILD_DIR)
+	@mkdir -p $(dir $@)
+	$(cc) $(CFLAGS) -c $< -o $@
+
+debug: CFLAGS=$(CFLAGS_DEBUG)
+debug: clean $(TARGET)
+
+clean:
+	rm -rf $(BUILD_DIR) $(BIN_DIR)
+
+rebuild: clean all
+.PHONY: all clean rebuild debug