documentation: fix alphabetic ordered list for git-rebase man page An alphabetic ordered list (a.) is converted to numerical in the man page (1.) so context comments naming 'a' were confusing, fix that by not using ordered list notation for 'a' anb 'b' items. Signed-off-by: Nelson Benitez Leon <nelsonjesus.benitez@seap.minhap.es> Signed-off-by: Junio C Hamano <gitster@pobox.com>