[feat] Linux downloads (#24)

* Added linux download URL.

* Update editor-installers.json

Author: neogeek

bin/index.js

@@ -59,6 +59,7 @@ const cli = meow(
 
 const osKeyMap = {
     'Darwin': 'mac',
+    'Linux': 'linux',
     'Windows_NT': 'win64'
 };