Update README.md

Author: paultyng

README.md

@@ -4,7 +4,7 @@ Otto
 ![Otto](https://cloud.githubusercontent.com/assets/37534/10147078/d400509e-65e0-11e5-9d66-c419914cbcf4.png)
 
 Otto is no longer actively developed or maintained. Please see the
-[announcement](https://www.hashicorp.com/blog/decommissioning-otto.html) for
+[announcement](https://web.archive.org/web/20190506063632/https://www.hashicorp.com/blog/decommissioning-otto.html) for
 more details.
 
 A tarball of the source is [available here](https://s3.amazonaws.com/hc-public/tools/otto-master.tbz2),