fix typing and add a note to the description that this string can be comma delimited for multiple domains

Author: MarcDerhammer

src/Options/Definitions.js

@@ -81,7 +81,8 @@ module.exports.ParseServerOptions = {
   },
   allowOrigin: {
     env: 'PARSE_SERVER_ALLOW_ORIGIN',
-    help: 'Sets the origins to Access-Control-Allow-Origin',
+    help:
+      'Sets the origin to Access-Control-Allow-Origin. Can be comma delimited if multiple should be supported',
   },
   analyticsAdapter: {
     env: 'PARSE_SERVER_ANALYTICS_ADAPTER',

src/Options/docs.js

@@ -61,8 +61,8 @@ export interface ParseServerOptions {
   appName: ?string;
   /* Add headers to Access-Control-Allow-Headers */
   allowHeaders: ?(string[]);
-  /* Sets the origins to Access-Control-Allow-Origin */
-  allowOrigin: ?(string[]);
+  /* Sets the origin to Access-Control-Allow-Origin. Can be comma delimited to support multiple */
+  allowOrigin: ?string;
   /* Adapter module for the analytics */
   analyticsAdapter: ?Adapter<AnalyticsAdapter>;
   /* Adapter module for the files sub-system */