Update installation instructions

app/views/docs/record.html.slim

@@ -4,12 +4,11 @@ markdown:
 
   ## 1. Install recorder
 
-  ### Linux
+  ### Arch Linux
 
-  To install/update asciinema recorder, open a terminal and run following
-  command:
+  asciinema is included in the [AUR](https://aur.archlinux.org/packages/asciinema/):
 
-      $ curl -sL get.asciinema.org | bash
+      $ yaourt -S asciinema
 
   ### OSX (via Homebrew)
 
@@ -17,13 +16,14 @@ markdown:
 
       $ brew install https://gist.github.com/rogeriopradoj/6672302/raw/4cb8e7054ea01b29f67a7e2e2475a4028c553071/asciinema.rb --HEAD 
 
-  Later update with:
+  Later upgrade with:
 
       $ brew upgrade asciinema
 
-  ### OSX (no Homebrew)
+  ### Others
 
-  If you don't use Homebrew then install/update with:
+  To install/upgrade asciinema recorder, open a terminal and run following
+  command:
 
       $ curl -sL get.asciinema.org | bash