Add hyperlink to Let's Encrypt
Hyperlink was not linked to anything before. It should link to
@@ -79,7 +79,7 @@ And then the swagger-parser will _ignore_ invalid certificates. Of course this
working inside a firewall or really know what you're doing, well, there's your rope.
### Dealing with Let's Encrypt
-Depending on the version of Java that you use, certificates signed by the [Let's Encrypt]() certificate authority _may not work_
+Depending on the version of Java that you use, certificates signed by the [Let's Encrypt](https://letsencrypt.org) certificate authority _may not work_
by default. If you are using any version of Java prior to 1.8u101, you most likely _must_ install an additional CA in your
JVM. Also note that 1.8u101 may _not_ be sufficient on it's own. Some users have reported that certain operating systems are
not accepting Let's Encrypt signed certificates.
