Add precise input method, enabled for public bookcases

Customizations/JSON/LayerConfigJson.ts

@@ -217,6 +217,16 @@ export interface LayerConfigJson {
          * (The first sentence is until the first '.'-character in the description)
          */
         description?: string | any,
+
+        /**
+         * If set, the user will prompted to confirm the location before actually adding the data.
+         * THis will be with a 'drag crosshair'-method.
+         * 
+         * If 'preferredBackgroundCategory' is set, the element will attempt to pick a background layer of that category.
+         */
+        preciseInput?: true | {
+            preferredBackground: "osmbasedmap" | "photo" | "historicphoto" | "map"
+        }
     }[],
 
     /**