Merge pull request #151 from dstansby/broken-link

Fix broken link

cheatsheets.tex

@@ -1019,7 +1019,7 @@
  \href{https://yt-project.org/doc/index.html}{\textbf{yt}}: Volumetric data visualization\\
  \href{https://mpld3.github.io}{\textbf{mpld3}}: Bringing Matplotlib to the browser\\
  \href{https://datashader.org/}{\textbf{Datashader}}: Large data processing pipeline\\
- \href{https://plotnine.readthedocs.io/en/latest/}{\textbf{plotnine}}: A grammar of graphics for Python
+ \href{https://plotnine.org/}{\textbf{plotnine}}: A grammar of graphics for Python
  \end{myboxed}
  %
  \begin{center}