Added rules for documentation

Makefile

@@ -8,7 +8,7 @@
 CC = gcc
 CFLAGS = -std=c99 -pedantic -Wall -D_DEFAULT_SOURCE -D_BSD_SOURCE -D_SVID_SOURCE -D_POSIX_C_SOURCE=200809L -g -c
 
-.PHONY: all clean
+.PHONY: all clean docs docs_clean
 
 all: supervisor generator
 
@@ -21,5 +21,11 @@ generator: generator.o
 %.o: %.c common.h
 	$(CC) $(CFLAGS) $^
 
+docs:
+	doxygen Doxyfile
+
 clean:
 	rm -f supervisor.o supervisor generator.o generator common.h.gch
+
+docs_clean:
+	rm -rf html