email: add import calendar action

+mail.el

@@ -89,6 +89,14 @@
   (map! :map mu4e-headers-mode-map
         :vne "l" #'max/mu4e-org-capture)
 
+  (add-to-list 'mu4e-view-mime-part-actions
+    '(:name "calendar"
+      :handler (lambda (file)
+                 (shell-command
+                  (format "khal import --batch %s" file))
+                 (khalel-import-events))
+      :receives temp))
+
   ;; Sign sent email automatically
   ;; (add-hook 'message-send-hook 'mml-secure-message-sign-smime)