automate wellknown setup

the main reason this is under app and not domain is because it let's
the user know that an app has to be installed for the whole thing to work.

part of #703

src/nginxconfig.ejs

@@ -162,9 +162,9 @@ server {
     }
 
     # user defined .well-known resources
-    location ~ ^/.well-known/(.*)$ {
-        root /home/yellowtent/boxdata/well-known/$host;
-        try_files /$1 @wellknown-upstream;
+    location /.well-known/ {
+        error_page 404 = @wellknown-upstream;
+        proxy_pass http://127.0.0.1:3000/well-known-handler/;
     }
 
 <% if (proxyAuth.enabled) { %>