r/webites: Add apps.du5t1n.xyz F-Droid repo

I want to publish the _20125_ Status application to an F-Droid
repository to make it easy for Tabitha to install and update.  F-Droid
repositories are similar to other package repositories: a collection of
packages and some metadata files.  Although there is a fully-fledged
server-side software package that can manage F-Droid repositories, it's
not required: the metadata files can be pre-generated and then hosted by
a static web server just fine.

This commit adds configuration for the web server and reverse proxy to
host the F-Droid repository at _apps.du5t1n.xyz_.

roles/websites/apps.du5t1n.xyz/meta/main.yml

@@ -0,0 +1,7 @@
+dependencies:
+- role: cert
+  vars:
+    cert_src: websites/apps.du5t1n.xyz.cer
+    cert_dest: /etc/pki/tls/certs/apps.du5t1n.xyz.cer
+    cert_key_src: websites/apps.du5t1n.xyz.key
+    cert_key_dest: /etc/pki/tls/private/apps.du5t1n.xyz.key