Update README.md (#538)

README.md

@@ -343,7 +343,7 @@ none | No digital signature or MAC value included
 
 First of all, we recommend to think carefully if auto-refreshing a JWT will not introduce any vulnerability in your system.
 
-We are not comfortable including this as part of the library, however, you can take a look to [this example](https://gist.github.com/ziluvatar/a3feb505c4c0ec37059054537b38fc48) to show how this could be accomplished.
+We are not comfortable including this as part of the library, however, you can take a look at [this example](https://gist.github.com/ziluvatar/a3feb505c4c0ec37059054537b38fc48) to show how this could be accomplished.
 Apart from that example there are [an issue](https://github.com/auth0/node-jsonwebtoken/issues/122) and [a pull request](https://github.com/auth0/node-jsonwebtoken/pull/172) to get more knowledge about this topic.
 
 # TODO