chore: add a little explanation

main_form.cs

@@ -82,6 +82,7 @@ namespace KRY_0x01_ng
             string str_to_check = String.Join("", tb_k.Text.ToUpper().Distinct());
             if (str_to_check.Length < 9)
             {
+                /* because why not, 8 is still lame */
                 MessageBox.Show($"The key is too short ({str_to_check.Length} characters).\nKey requirements: 9-25 unique alphabetic characters", "Error");
                 return;
             }