git-prompt: put upstream comments together

Commit 6d158cba28 (bash completion: Support "divergence from upstream"
messages in __git_ps1, 2010-06-17) introduced support for indicating
divergence from upstream in the PS1 prompt. The comments at the top of
git-prompt.sh that were introduced with that commit are several
paragraphs long. Over the years, other comments have been inserted in
between the paragraphs relating to divergence from upstream.

This commit puts the comments relating to divergence from upstream back
together.

Signed-off-by: Justin Donnelly <justinrdonnelly@gmail.com>
Reviewed-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/completion/git-prompt.sh

@@ -66,6 +66,11 @@
 #     git           always compare HEAD to @{upstream}
 #     svn           always compare HEAD to your SVN upstream
 #
+# By default, __git_ps1 will compare HEAD to your SVN upstream if it can
+# find one, or @{upstream} otherwise.  Once you have set
+# GIT_PS1_SHOWUPSTREAM, you can override it on a per-repository basis by
+# setting the bash.showUpstream config variable.
+#
 # You can change the separator between the branch name and the above
 # state symbols by setting GIT_PS1_STATESEPARATOR. The default separator
 # is SP.
@@ -79,11 +84,6 @@
 # single '?' character by setting GIT_PS1_COMPRESSSPARSESTATE, or omitted
 # by setting GIT_PS1_OMITSPARSESTATE.
 #
-# By default, __git_ps1 will compare HEAD to your SVN upstream if it can
-# find one, or @{upstream} otherwise.  Once you have set
-# GIT_PS1_SHOWUPSTREAM, you can override it on a per-repository basis by
-# setting the bash.showUpstream config variable.
-#
 # If you would like to see more information about the identity of
 # commits checked out as a detached HEAD, set GIT_PS1_DESCRIBE_STYLE
 # to one of these values: