Updated Installation (markdown)

Installation.md

@@ -8,6 +8,15 @@
 
 <sup>1</sup> The port will be opened on the firewall (if enabled) for the private profile only, if you're connected to a domain or a public network the port will not be opened automatically, but can be done so manually.
 
+# macOS #
+
+### Manually ###
+* Download latest version of Lidarr's OSX package from https://github.com/lidarr/Lidarr/releases
+* Open the archive and drag the Lidarr icon to your Application folder.
+  * **Note:** _In macOS 10.12+ Gatekeeper App Translocation will prevent Lidarr run directly from the Downloads folder from updating_
+* Open Lidarr.app
+* You should now be able to access Lidarr at [http://localhost:8686](http://localhost:8686)
+
 # Docker #
 #### Docker is available on Linux, macOS and Windows ####