patchbomb: fix help to reflect actual operation

In the body, the description is shown in its entirety,
unstripped from what was already in the subject.

hgext/patchbomb.py

@@ -14,7 +14,7 b' Each patch email has a Subject line of "'
 first line of the changeset description as the subject text. The
 message contains two or three body parts:
 
-  The remainder of the changeset description.
+  The changeset description.
 
   [Optional] The result of running diffstat on the patch.
 
@@ -187,10 +187,10 b' def patchbomb(ui, repo, *revs, **opts):'
 
     Each patch email has a Subject line of "[PATCH M of N] ...", using
     the first line of the changeset description as the subject text.
-    The message contains two or three body parts. First, the rest of
-    the changeset description. Next, (optionally) if the diffstat
-    program is installed, the result of running diffstat on the patch.
-    Finally, the patch itself, as generated by "hg export".
+    The message contains two or three parts. First, the changeset
+    description. Next, (optionally) if the diffstat program is
+    installed, the result of running diffstat on the patch. Finally,
+    the patch itself, as generated by "hg export".
 
     With -o/--outgoing, emails will be generated for patches not found
     in the destination repository (or only those which are ancestors