Update documentation files.
diff --git a/runtime/doc/help.txt b/runtime/doc/help.txt
index 77562f9..3ec4ab4 100644
--- a/runtime/doc/help.txt
+++ b/runtime/doc/help.txt
@@ -144,6 +144,7 @@
 |hebrew.txt|	Hebrew language support and editing
 |russian.txt|	Russian language support and editing
 |ft_ada.txt|	Ada (the programming language) support
+|ft_sql.txt|	about the SQL filetype plugin
 |hangulin.txt|	Hangul (Korean) input mode
 |rileft.txt|	right-to-left editing mode