add algo class

algorigrame.d2

@@ -0,0 +1,33 @@
+classes: {
+  q: {
+    shape: diamond
+  }
+  start: {
+    shape: oval
+    label: Début
+    near: top-center
+  }
+  end: {
+    shape: oval
+    label: Fin
+    near: bottom-center
+  }
+  comment: {
+    style: {
+      stroke-dash: 3
+    }
+  }
+  y: {
+    source-arrowhead.label: yes
+    style.stroke: green
+    source-arrowhead.style.font-color: green
+  }
+  n: {
+    source-arrowhead.label: no
+    style.stroke: red
+    source-arrowhead.style.font-color: red
+  }
+}
+direction: down
+start.class: start
+end.class: end