Update manpage for double-star support

yadm.1

@@ -692,10 +692,12 @@ For example:
     .gnupg/*.gpg
 .RE
 
-Standard filename expansions (*, ?, [) are supported. Other shell expansions
-like brace and tilde are not supported. Spaces in paths are supported, and
-should not be quoted. If a directory is specified, its contents will be
-included, but not recursively. Paths beginning with a "!" will be excluded.
+Standard filename expansions (*, ?, [) are supported.
+If you have Bash version 4, you may use "**" to match all subdirectories.
+Other shell expansions like brace and tilde are not supported.
+Spaces in paths are supported, and should not be quoted.
+If a directory is specified, its contents will be included, but not recursively.
+Paths beginning with a "!" will be excluded.
 
 The
 .B yadm encrypt