Add rule for notes and better escaping in errors.

app/Http/Requests/BillUpdateRequest.php

@@ -81,6 +81,7 @@ class BillUpdateRequest extends FormRequest
             'repeat_freq'             => sprintf('required|in:%s', join(',', config('firefly.bill_periods'))),
             'skip'                    => 'required|integer|gte:0|lte:31',
             'active'                  => 'boolean',
+            'notes'                   => 'between:1,65536|nullable',
         ];
     }
 }