update developer-guide

Signed-off-by: weichen <niweichen@chinamobile.com>
Change-Id: I42162ee7ea5d0c74baa4abdd7b1428d6a1f51dbe
diff --git a/docs/developer-guide.rst b/docs/developer-guide.rst
index ed1c4ee..4707804 100644
--- a/docs/developer-guide.rst
+++ b/docs/developer-guide.rst
@@ -5,8 +5,8 @@
    :depth: 3
    :local:
 
-Developer-Guides
-================
+Developer-Guide
+===============
 
 
 .. note: