t3404 (rebase -i): move comment to description

Add a comment describing the setup in t3404 to its --help output.

This should make it easier to decide where to put new functions
without disrupting the flow of the file or obstructing the description
of the test setup.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t3404-rebase-interactive.sh

@@ -7,34 +7,33 @@ test_description='git rebase interactive
 
 This test runs git rebase "interactively", by faking an edit, and verifies
 that the result still makes sense.
+
+Initial setup:
+
+     one - two - three - four (conflict-branch)
+   /
+ A - B - C - D - E            (master)
+ | \
+ |   F - G - H                (branch1)
+ |     \
+ |\      I                    (branch2)
+ | \
+ |   J - K - L - M            (no-conflict-branch)
+  \
+    N - O - P                 (no-ff-branch)
+
+ where A, B, D and G all touch file1, and one, two, three, four all
+ touch file "conflict".
 '
 . ./test-lib.sh
 
 . "$TEST_DIRECTORY"/lib-rebase.sh
 
 set_fake_editor
 
-# Set up the repository like this:
-#
-#     one - two - three - four (conflict-branch)
-#   /
-# A - B - C - D - E            (master)
-# | \
-# |   F - G - H                (branch1)
-# |     \
-# |\      I                    (branch2)
-# | \
-# |   J - K - L - M            (no-conflict-branch)
-#  \
-#    N - O - P                 (no-ff-branch)
-#
-# where A, B, D and G all touch file1, and one, two, three, four all
-# touch file "conflict".
-#
 # WARNING: Modifications to the initial repository can change the SHA ID used
 # in the expect2 file for the 'stop on conflicting pick' test.
 
-
 test_expect_success 'setup' '
 	test_commit A file1 &&
 	test_commit B file1 &&