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/files/apps.du5t1n.xyz.httpd.conf

@@ -0,0 +1,23 @@
+<VirtualHost _default_:80>
+ServerName apps.du5t1n.xyz
+
+RewriteEngine On
+RewriteRule (.*) https://%{SERVER_NAME}$1 [R=301,L]
+</VirtualHost>
+
+<VirtualHost _default_:443>
+ServerName apps.du5t1n.xyz
+
+Include conf.d/ssl.include
+SSLCertificateKeyFile /etc/pki/tls/private/apps.du5t1n.xyz.key
+SSLCertificateFile /etc/pki/tls/certs/apps.du5t1n.xyz.cer
+
+<IfModule mod_headers.c>
+	Header always set Strict-Transport-Security "max-age=63072000; includeSubDomains"
+</IfModule>
+
+DocumentRoot /srv/www/apps.du5t1n.xyz/htdocs
+<Directory /srv/www/apps.du5t1n.xyz/htdocs>
+	Require all granted
+</Directory>
+</VirtualHost>