cosmetics: change from 'See-Also' to 'See Also'

Changes the documentation that uses 'See-Also' to the more common
'See Also' form.

Signed-off-by: Junio C Hamano <junkio@cox.net>

Documentation/git-pack-objects.txt

@@ -101,7 +101,7 @@ Documentation
 -------------
 Documentation by Junio C Hamano
 
-See-Also
+See Also
 --------
 gitlink:git-repack[1]
 gitlink:git-prune-packed[1]

Documentation/git-pack-redundant.txt

@@ -46,7 +46,7 @@ Documentation
 --------------
 Documentation by Lukas Sandström <lukass@etek.chalmers.se>
 
-See-Also
+See Also
 --------
 gitlink:git-pack-objects[1]
 gitlink:git-repack[1]

Documentation/git-prune-packed.txt

@@ -40,7 +40,7 @@ Documentation
 --------------
 Documentation by Ryan Anderson <ryan@michonline.com>
 
-See-Also
+See Also
 --------
 gitlink:git-pack-objects[1]
 gitlink:git-repack[1]

Documentation/git-repack.txt

@@ -63,7 +63,7 @@ Documentation
 --------------
 Documentation by Ryan Anderson <ryan@michonline.com>
 
-See-Also
+See Also
 --------
 gitlink:git-pack-objects[1]
 gitlink:git-prune-packed[1]