Improve the document structure in several places

Change-Id: Icea6d0b0d9628eb171f5673b397f1db7f1c5c5b8
diff --git a/data.rst b/data.rst
index b225131..221a994 100644
--- a/data.rst
+++ b/data.rst
@@ -1,4 +1,4 @@
-.. _data:
+.. _Data:
 
 Data Packet
 -----------