nixos/librenms: fix documentation link formatting

nixos/modules/services/monitoring/librenms.nix

@@ -344,9 +344,9 @@ in
       };
       description = ''
         Attrset of the LibreNMS configuration.
-        See https://docs.librenms.org/Support/Configuration/ for reference.
+        See <https://docs.librenms.org/Support/Configuration/> for reference.
         All possible options are listed [here](https://github.com/librenms/librenms/blob/master/misc/config_definitions.json).
-        See https://docs.librenms.org/Extensions/Authentication/ for setting other authentication methods.
+        See <https://docs.librenms.org/Extensions/Authentication/> for setting other authentication methods.
       '';
       default = { };
       example = {
@@ -361,7 +361,7 @@ in
       default = null;
       description = ''
         Additional config for LibreNMS that will be appended to the `config.php`. See
-        https://github.com/librenms/librenms/blob/master/misc/config_definitions.json
+        <https://github.com/librenms/librenms/blob/master/misc/config_definitions.json>
         for possible options. Useful if you want to use PHP-Functions in your config.
       '';
     };