Documentation: full-ness of a bundle is significant for cloning

Not necessarily every bundle file can be cloned from.  Only the ones
that do not need prerequisites can.

When 1d52b02 (Documentation: minor grammatical fixes and rewording
in git-bundle.txt, 2009-03-22) reworded this paragraph, it lost a
critical hint to tell readers why this particular bundle can be
cloned from.  Resurrect it.

Signed-off-by: Junio C Hamano <[email protected]>

Author: gitster

Documentation/git-bundle.txt

@@ -112,10 +112,9 @@ machineA$ git bundle create file.bundle master
 machineA$ git tag -f lastR2bundle master
 ----------------
 
-Then you transfer file.bundle to the target machine B. If you are creating
-the repository on machine B, then you can clone from the bundle as if it
-were a remote repository instead of creating an empty repository and then
-pulling or fetching objects from the bundle:
+Then you transfer file.bundle to the target machine B. Because this
+bundle does not require any existing object to be extracted, you can
+create a new repository on machine B by cloning from it:
 
 ----------------
 machineB$ git clone -b master /home/me/tmp/file.bundle R2