Merge pull request #452 from nickmccurdy/patch-1

Use recommended exec-path-from-shell predicate

README.md

@@ -251,7 +251,7 @@ In another example, we can load things conditional on the operating system:
 
 ```
 (use-package exec-path-from-shell
-  :if (eq system-type 'darwin)
+  :if (memq window-system '(mac ns))
   :ensure t
   :config
   (exec-path-from-shell-initialize))