documentclass{article}
usepackage{hyperref}
usepackage{bookmark}
newcommand{cmd}[1]{pdfbookmark[2]{#1}{unixcommand}textcolor{blue}{texttt{{large #1}}}}
begin{document}
cmd{ls} → list the files
begin{itemize}
  item texttt{-l} = foo bar
end{itemize}
end{document}