Fix figure title

The orphan blob d670460b4b4aece5915caf5c68d12f560a9fe3e4 is not in the
figure. So the figure is not of "All the objects" but rather all the
reachable ones.

Author: Mashrur Mia (Sa'ad)

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

@@ -328,7 +328,7 @@ $ find .git/objects -type f
 
 If you follow all the internal pointers, you get an object graph something like this:
 
-.All the objects in your Git directory.
+.All the reachable objects in your Git directory.
 image::images/data-model-3.png[All the objects in your Git directory.]
 
 ==== Object Storage