Resolve "Ouvrages: modifier les types d'ouvrages"

Closes #511 (closed)

docs/en/calculators/pam/macrorugo.md

@@ -25,3 +25,8 @@ It requires the following values to be entered:
 - The width of the blocks \(D\) facing the flow (m);
 - The useful height of the blocks \(k\) (m);
 - The drag coefficient of a single block (1 for round, 2 for square).
+
+<div style="position: relative"><a id="rugosite-de-fond" style="position: absolute; top: -60px;"></a></div>
+# Bed roughness
+
+![](schema_rugosite_fond.png)