Add cartography menu with image overlays (WIP)

webgis/js/state.js

@@ -11,10 +11,11 @@
 /**
  * @typedef {Object} GisStateType
  * @property {L.Map|null} map
- * @property {String|null} apiUrl
  * @property {MarkerLookup} markers
  * @property {LayerGroupLookup} layers
  * @property {Object|null} bibliography
+ * @property {String|null} apiUrl
+ * @property {Object} cartography
  */
 
 /** @type {GisStateType} */
@@ -36,6 +37,9 @@ export const GisState = {
     },
     bibliography: null,
     apiUrl : null,
+    cartography : {
+        historic: [],
+    }
 }
 
 /**