docs: add link to tecff/site-ffa (Altdorf, Landshut & Umgebung)

docs/user/site.rst

@@ -362,6 +362,7 @@ site-repos in the wild
 
 This is a non-exhaustive list of site-repos from various communities:
 
+* `site-ffa <https://github.com/tecff/site-ffa>`_ (Altdorf, Landshut & Umgebung)
 * `site-ffbs <https://github.com/ffbs/site-ffbs>`_ (Braunschweig)
 * `site-ffhb <https://github.com/FreifunkBremen/gluon-site-ffhb>`_ (Bremen)
 * `site-ffda <https://github.com/freifunk-darmstadt/site-ffda>`_ (Darmstadt)