Updated Installation (markdown)

Installation.md

@@ -10,7 +10,7 @@ Radarr is now installed as a service set to auto start, check that it is running
 
 Don't forget to use UNC paths like `\\Server\Share` instead of mapped network drives like `M:\Movies`.
 
-### Debian/Ubuntu ###
+### Debian / Ubuntu ###
 
 Install dependencies:
 
@@ -32,7 +32,7 @@ Now proceed to [Manually Install Radarr](/Radarr/Radarr/wiki/Installation#manual
 
 [Radarr AUR package](https://aur.archlinux.org/packages/radarr/)
 
-    pacaur -S radarr
+    aurman -S radarr
 
 ### Manually Install Radarr ###