This prevents emacs from turning it into a fancy, non-evaluable
docstring (and also makes it easier to deal with during extraction to
sphinx).
Here is an example of how to color search results based on tags.
(the following text would be placed in your ~/.emacs file):
- (setq notmuch-search-line-faces '((\"unread\" . (:foreground \"green\"))
+ (setq notmuch-search-line-faces \\='((\"unread\" . (:foreground \"green\"))
(\"deleted\" . (:foreground \"red\"
:background \"blue\"))))