Fix grammar error in readme.md

Michael Dunn · web-flow · commit 0e2272b1af4f · 2017-01-05T14:56:12.000-05:00
There is a small verb tense error that needs fixing.

Cheers!
diff --git a/README.md b/README.md
@@ -41,7 +41,7 @@ Swagger UI works in all evergreen desktop browsers (Chrome, Safari, Firefox). In
 ### Build
 You can rebuild swagger-ui on your own to tweak it or just so you can say you did.  To do so, follow these steps:
 
-### Windows Users: Please install [Python](https://www.python.org/downloads/windows/) before follow below guidelines for node-gyp rebuild to run.
+### Windows Users: Please install [Python](https://www.python.org/downloads/windows/) before following the guidelines below for node-gyp rebuild to run.
 
 1. `npm install`
 2. `npm run build`
