diff: undocument the compaction heuristic knobs for experimentation

It seems that people around here are all happy with the updated
heuristics used to decide where the hunks are separated.  Let's keep
that as the default.  Even though we do not expect too much trouble
from the difference between the old and the new algorithms, just in
case let's leave the implementation of the knobs to turn it off for
emergencies.  There is no longer need for documenting them, though.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/diff-config.txt

@@ -166,11 +166,6 @@ diff.tool::
 
 include::mergetools-diff.txt[]
 
-diff.compactionHeuristic::
-	Set this option to enable an experimental heuristic that
-	shifts the hunk boundary in an attempt to make the resulting
-	patch easier to read.
-
 diff.algorithm::
 	Choose a diff algorithm.  The variants are as follows:
 +

Documentation/diff-options.txt

@@ -63,12 +63,6 @@ ifndef::git-format-patch[]
 	Synonym for `-p --raw`.
 endif::git-format-patch[]
 
---compaction-heuristic::
---no-compaction-heuristic::
-	These are to help debugging and tuning an experimental
-	heuristic that shifts the hunk boundary in an attempt to
-	make the resulting patch easier to read.
-
 --minimal::
 	Spend extra time to make sure the smallest possible
 	diff is produced.