fix link to WKD article (thanks, micah)

content/dane-openpgpkey-for-debian.org.md

@@ -7,7 +7,7 @@ DANE OPENPGPKEY for debian.org
 ==============================
 
 I recently announced [the publication of Web Key Directory for
-`@debian.org` e-mail addresses](wkd-for-debian.org).  This blog post
+`@debian.org` e-mail addresses](wkd-for-debian.org.html).  This blog post
 announces another way to fetch OpenPGP certificates for `@debian.org`
 e-mail addresses, this time using only the DNS.  These two mechanisms
 are complementary, not in competition.  We want to make sure that