Make new.txt example consistent

Author: crd

book/10-git-internals/sections/objects.asc

@@ -192,7 +192,7 @@ $ git update-index test.txt
 $ git update-index --add new.txt
 ----
 
-Your staging area now has the new version of `test.txt` as well as the new file new.txt.
+Your staging area now has the new version of `test.txt` as well as the new file `new.txt`.
 Write out that tree (recording the state of the staging area or index to a tree object) and see what it looks like:
 
 [source,console]