NEW: Add makefile

Added makefile to compile project, generate docs and archive.

makefile

+CC = gcc
+CFLAGS = -Wall -Wextra
+SOURCES = $(wildcard *.c)
+HEADERS = $(wildcard *.h)
+OBJECTS = $(SOURCES:.c=.o)
+MAKEFILE = makefile
+README = README.md
+DOXYFILE = Doxyfile
+DOXYGEN = doxygen
+DOXYGEN_FLAGS =
+LEVELS = $(wildcard level*.txt)
+ARCHIVE_NAME = ERKEN_Efe.tar.gz
+ARCHIVE_SOURCES = $(SOURCES) $(HEADERS) $(MAKEFILE) $(LEVELS) $(README) $(DOXYFILE)
+ARCHIVE = tar
+ARCHIVE_FLAGS = -cvzf
+EXEC = sokoban
+
+$(EXEC) : $(OBJECTS)
+	$(CC) $(CFLAGS) -o $@ $^
+
+%.o : %.c
+	$(CC) $(CFLAGS) -c $<
+
+clean :
+	rm sokoban
+	rm *.o
+
+doc :
+	$(DOXYGEN) $(DOXYGEN_FLAGS)
+
+archive : $(ARCHIVE_SOURCES)
+	$(ARCHIVE) $(ARCHIVE_FLAGS) $(ARCHIVE_NAME) $^
+