update the showcase instructions to be more specific

Summary:
I updated the showcase instructions during the docdown but after getting some more requests I think these should be more specific.

Two things in particular. It isn't very useful to link to some generic page on the company's own website, especially if the company has zero news coverage. Secondly, this content should be in English because that's what most readers know.

So I just updated the instructions to say this.
Closes facebook#8788

Differential Revision: D3564132

Pulled By: JoelMarcey

fbshipit-source-id: d75adda0d2161e795436d0075b814a40c69383a3

website/src/react-native/showcase.js

@@ -10,14 +10,12 @@
 /*
 Thousands of applications use React Native, so we can't list all of them
 in our showcase. To be useful to someone looking through the showcase,
-either the app must be something that a significant number of readers would recognize, or the makers of the application must have posted something valuable technically about the making of the app. So, one of the following should hold:
+either the app must be something that most readers would recognize, or the makers of the application must have posted useful technical content about the making of the app. It also must be useful considering that the majority of readers only speak English. So, each app in the showcase should link to either:
 
-1/ The app is branded with a public company brand
-2/ The app received some publicity in top-tier news
-3/ The app is made by a funded startup
-4/ A popular piece of developer content discusses this app
+1/ An English-language news article discussing the app, built either by a funded startup or for a public company
+2/ An English-language technical blog post by the app creators specifically discussing React Native
 
-For each app in the showcase, use infoLink and infoTitle to reference content that would be relevant to a React Native developer learning about this app.
+For each app in the showcase, use infoLink and infoTitle to reference this content.
 */
 
 var React = require('React');