docs: def add_image(self, figure, dpi=72):
          '''
          Adds an image to the last chapter/section.
          The image will be stored in the `{self.title}_files` directory.
  
          :param matplotlib.figure figure:
              A matplotlib figure to be saved into the report
          '''
          name = os.path.join(self._dir, '/fig%s.png' % self.fig_counter)
          self.fig_counter += 1
          figure.savefig(name, dpi=dpi)
          plt.close(figure)
          self.body += '<img src="%s" />\n' % name