feat(tazjin): tazjin

tazjin: https://github.com/tazjin/tazjin/issues/1
Change-Id: I655670fed1dd1ba7e9034f165238e2d69b228ee5
Reviewed-on: https://cl.tvl.fyi/c/depot/+/1002
Tested-by: BuildkiteCI
Reviewed-by: lukegb <lukegb@tvl.fyi>

users/tazjin/nixos/camden/default.nix

@@ -381,6 +381,10 @@ in lib.fix(self: {
           try_files $uri $uri.html $uri/ =404;
         }
 
+        location = /tazjin {
+          return 200 "tazjin";
+        }
+
         location /blobs/ {
           alias /var/www/blobs/;
         }