build: switch from yarn to npm to manage js dependencies and move js contents to root

yarn v1 is being deprecated and starts to have some issues

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

src/shims-vue.d.ts

@@ -0,0 +1,16 @@
+declare module "*.vue" {
+  import type { DefineComponent } from "vue";
+
+  // eslint-disable-next-line @typescript-eslint/ban-types
+  const component: DefineComponent<{}, {}, {}>;
+  export default component;
+}
+
+declare module "*.svg" {
+  import Vue, { VueConstructor } from "vue";
+
+  const content: VueConstructor<Vue>;
+  export default content;
+}
+
+declare module "@vue-leaflet/vue-leaflet";