Add Example usage section to help menu

[ehsandeep]

From FFuF:-

EXAMPLE USAGE:
  Fuzz file paths from wordlist.txt, match all responses but filter out those with content-size 42.
  Colored, verbose output.
    ffuf -w wordlist.txt -u https://example.org/FUZZ -mc all -fs 42 -c -v

  Fuzz Host-header, match HTTP 200 responses.
    ffuf -w hosts.txt -u https://example.org/ -H "Host: FUZZ" -mc 200

  Fuzz POST JSON data. Match all responses not containing text "error".
    ffuf -w entries.txt -u https://example.org/ -X POST -H "Content-Type: application/json" \
      -d '{"name": "FUZZ", "anotherkey": "anothervalue"}' -fr "error"

  Fuzz multiple locations. Match only responses reflecting the value of "VAL" keyword. Colored.
    ffuf -w params.txt:PARAM -w values.txt:VAL -u https://example.org/?PARAM=VAL -mr "VAL" -c

  More information and examples: https://github.com/ffuf/ffuf