\usepackage{hyperref}%comment out if this causes trouble. Otherwise, this makes references in the document clickable.
\usepackage{todonotes}%allows for the \todo{...} and \todo[inline]{...} commands
\usepackage{cleveref}%use \Cref instead of \ref to reference labels (e.g. \label{def:ddh}). Allows for example \Cref{def:ddh} which is rendered as Definition X.Y. Documentation: https://mirror.physik.tu-berlin.de/pub/CTAN/macros/latex/contrib/cleveref/cleveref.pdf