feat: add -D CLI option to enable definition lists - #972

error: unused return value of `exec` that must be used
   --> dos-fuzzer/src/main.rs:282:25
    |
282 |                         Command::new(&args[0]).args(&args[1..]).exec();
    |                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: `-D unused-must-use` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(unused_must_use)]`
help: use `let _ = ...` to ignore the resulting value
    |
282 |                         let _ = Command::new(&args[0]).args(&args[1..]).exec();
    |                         +++++++

error: could not compile `dos-fuzzer` (bin "dos-fuzzer") due to 1 previous error