\documentclass{article}


%%% Convenient todo command
\usepackage{xifthen}
\newcommand{\todo}[1][]{%
    \ifthenelse{\equal{#1}{}}% if no argument given
        { \emph{TODO}\Warning[TODO]{}}%
    %else
        {\emph{\uppercase{TODO}}\Warning[TODO]{#1}}%
}



\usepackage{tabularx}
\usepackage{float}
\RequirePackage[T1]{fontenc}
\usepackage{caption}
\usepackage{siunitx}
\usepackage{adjustbox}
\usepackage{bm}
\usepackage[perpage]{footmisc}
\usepackage{doi}
\usepackage{subcaption}

\begin{document}
\tableofcontents

%\include{introduction}
\include{theory}
\include{methods}
\include{results}
\include{discussion}
%\include{conclusion}


\end{document}