Fix linebreak for python command in sidebar
<a href="/materialize">materialize</a><br>
<a href="/merge">merge</a><br>
<a href="/mirror">mirror</a><br>
- <a href="/python">python</a>
+ <a href="/python">python</a><br>
<a href="/query">query</a><br>
<a href="/reason">reason</a><br>
<a href="/reduce">reduce</a><br>
