chore: update wording in option descriptions

module.nix

···
         default = { };
         example = lib.literalExpression ''
           {
-            # this is only an example, do NOT do this! your secret will end up readable by *everyone*!
-            KNOT_SERVER_SECRET = "verysecuresecret";
+            KNOT_SERVER_OWNER = "did:web:handle.invalid";
           }
         '';
         description = ''
           Additional environment variables. Use `environmentFile` for secrets.
 
-          `KNOT_SERVER_SECRET` must be set for the knotserver to work, and can be obtained from
-          [this page](https://tangled.sh/knots). Please set this with environmentFile instead of setting it here
-          directly.
+          `KNOT_SERVER_OWNER` must be set for the program to work correctly.
         '';
       };
 
···
         example = "/etc/tangled/knotserver.env";
         description = ''
           Environment file to set additional configuration and secrets for the knotserver.
-
-          `KNOT_SERVER_SECRET` must be set for the knotserver to work, and can be obtained from
-          [this page](https://tangled.sh/knots).
         '';
       };
     };