\documentclass[../dissertation.tex]{subfiles}

\begin{document}
\section{Time Spent}
\begin{figure}[h!]
  \centering
  % TODO make it show how many hours were spent instead of percentages
  \begin{tikzpicture}
    \pie[text=legend]{70/Coding, 20/Research}
  \end{tikzpicture}
  % TODO improve wording for figure caption
  \caption{Time spent on ... \textbf{Improve wording}}
\end{figure}

\end{document}