Started gitbook in docs folder

Change-Id: Ifda129c3202855bba16a7c77e35b4351c9773655
diff --git a/docs/.gitignore b/docs/.gitignore
new file mode 100644
index 0000000..8bec8ec
--- /dev/null
+++ b/docs/.gitignore
@@ -0,0 +1 @@
+_book/
\ No newline at end of file