Add a flowchart environnement and its listof

So we can more easily access those flowcharts from pdf and website,
rather than looking in the crowded list of figures.

book/bread-types/bread-types.tex

@@ -165,7 +165,7 @@ easiest way to start making great bread at home. With just a
 few steps, you can stop buying bread forever. This works with
 any flour, including gluten-free options.
 
-\begin{figure}[!htb]
+\begin{flowchart}[!htb]
 \begin{center}
   \input{figures/fig-process-flat-bread.tex}
   \caption[Flat bread process]{The process of making a flatbread is very
@@ -173,7 +173,7 @@ any flour, including gluten-free options.
       handy for busy bakers.}%
   \label{fig:flat-bread-process}
 \end{center}
-\end{figure}
+\end{flowchart}
 
 This is my go-to recipe that I~use to make bread whenever
 I~have little time or when I~am abroad. You can choose