Added documentation building to the build system. Use make doc.
diff --git a/Makefile.am b/Makefile.am
index 4103ac3..76541d7 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,2 +1,5 @@
 AUTOMAKE_OPTIONS = foreign
 SUBDIRS = src 
+
+doc:
+	doxygen doxygen.cfg