Added 'colorcolumn' option.  Partly by Gregor Uhlenheuer.
diff --git a/runtime/doc/syntax.txt b/runtime/doc/syntax.txt
index cd06f16..ebbe891 100644
--- a/runtime/doc/syntax.txt
+++ b/runtime/doc/syntax.txt
@@ -4212,6 +4212,8 @@
 'highlight' option default.  Note that the highlighting depends on the value
 of 'background'.  You can see the current settings with the ":highlight"
 command.
+							*hl-ColorColumn*
+ColorColumn	used for the columns set with 'colorcolumn'
 							*hl-Conceal*
 Conceal		placeholder characters substituted for concealed
 		text (see 'conceallevel')