doc/emacs: add notmuch-show-empty-saved-searches to manual

Answering a user question, I had to dig for this variable, but I think
it is a reasonably common customization wish, particularly for users
with custom count-functions.

diff --git a/doc/notmuch-emacs.rst b/doc/notmuch-emacs.rst
index fe132327edae33da7457d35655d8e5cb84876c14..189a51ad96f47552ffed0a27ec99677a9da84d98 100644 (file)
--- a/doc/notmuch-emacs.rst
+++ b/doc/notmuch-emacs.rst
@@ -94,6 +94,9 @@ customizing the variables
     - if you don't want to worry about all of this nonsense, leave
       this set to `t`.
 
+.. emacsvar:: notmuch-show-empty-saved-searches
+
+   |docstring::notmuch-show-empty-saved-searches|
 
 notmuch-hello key bindings
 --------------------------