Update the documentation string for notmuch-saved-searches to include
the new :search-type option.
:sort-order Specify the sort order to be used for the search.
Possible values are 'oldest-first 'newest-first or
nil. Nil means use the default sort order.
+ :search-type Specify whether to run the search in search-mode
+ or tree mode. Set to 'tree to specify tree
+ mode, set to nil (or anything except tree) to
+ specify search mode.
Other accepted forms are a cons cell of the form (NAME . QUERY)
or a list of the form (NAME QUERY COUNT-QUERY)."