Add Arch Linux icon

As requested in the issues. I choose to include the Trademark symbol
(#594 relevant) in this logo given the Logo Usage Guidelines over at
https://wiki.archlinux.org/index.php/DeveloperWiki:TrademarkPolicy#Logo_Usage_Guidelines

_data/simple-icons.json

@@ -120,6 +120,11 @@
             "hex": "000000",
             "source": "https://www.apple.com/itunes/marketing-on-music/identity-guidelines.html#apple-music-icon"
         },
+        {
+            "title": "Arch Linux",
+            "hex": "1793D1",
+            "source": "https://www.archlinux.org/art/"
+        },
         {
             "title": "Asana",
             "hex": "273347",

icons/archlinux.svg

@@ -0,0 +1 @@
+<svg aria-labelledby="simpleicons-archlinux-icon" role="img" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><title id="simpleicons-archlinux-icon">Arch Linux icon</title><path d="M11.390232.60509C10.375655 3.09168 9.764285 4.7185 8.63513 7.13162c.692712.734695 1.542857 1.589214 2.923032 2.553937-1.484256-.610496-2.49621-1.223615-3.25277-1.859475-1.444897 3.015743-3.710204 7.311953-8.30554 15.568513 3.612246-2.08513 6.411955-3.36997 9.020993-3.861516-.111954-.48105-.175802-1.003208-.17143-1.54723l.0035-.115453c.057725-2.314286 1.261224-4.09417 2.68688-3.972595 1.425656.119825 2.53382 2.095627 2.477843 4.409038-.010496.43557-.06035.85452-.146064 1.242857 2.58105.504665 5.351895 1.78688 8.914286 3.844024-.702333-1.29271-1.329447-2.4586-1.928572-3.569387-.943732-.731196-1.926822-1.6828-3.933236-2.71312 1.3793.3586 2.366764.77143 3.136443 1.23411C13.970407 7.010922 13.478862 5.503924 11.390232.60509zM22.897813 21.360193v-.623615h-.233528v-.083965h.561516v.083965h-.2344v.623615h-.093587M23.322886 21.360193v-.70758h.14169l.167056.501166c.015744.04723.027114.082215.03411.10583.007873-.025365.020118-.06385.038485-.113703l.168805-.493294h.126822v.70758h-.090962v-.593003l-.206414.593003h-.083965l-.204665-.602624v.602623h-.090962"/></svg>