adding operating guide

Change-Id: I6b77fc6f17fe3941af2b8679a626f85d6012a284
diff --git a/docs/Makefile b/docs/Makefile
new file mode 100644
index 0000000..a369a94
--- /dev/null
+++ b/docs/Makefile
@@ -0,0 +1,7 @@
+default: book
+
+book:
+	gitbook init; gitbook serve &
+
+clean:
+	rm -rf _book