doc/tutorial/basics: add per-page chapter headings

Change-Id: I9e0a6b5d1a1c820081b3f87c3871068ea042f889
diff --git a/doc/tutorial/basics/bottom.md b/doc/tutorial/basics/bottom.md
index c3cde6a..6a6ac5d 100644
--- a/doc/tutorial/basics/bottom.md
+++ b/doc/tutorial/basics/bottom.md
@@ -1,5 +1,7 @@
 [TOC](Readme.md) [Prev](duplicates.md) [Next](types.md)
 
+_Types and Values_
+
 # Bottom
 
 Specifying duplicate fields with conflicting values results in an error,