Update documentation

Author: verga

cp.html

@@ -210,7 +210,7 @@ <h3>Quantum phase transition in the mean-field and Markov&nbsp;approximations</h
 \end{equation}
 $$</div>
 <p>
-where u_\pm = u_0(\pm&nbsp;\bar{g}),
+where <span class="math">\(u_\pm = u_0(\pm \bar{g})\)</span>,
 </p>
 <div class="math">$$
 u_0(\bar{g}) = \exp\big[-\I J H_{0}(\bar{g})\big]