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/components/Utils/ObserverElement.vue

@@ -0,0 +1,35 @@
+<template>
+  <div class="observer" ref="observed" />
+</template>
+
+<script lang="ts" setup>
+import "intersection-observer";
+import { onMounted, onUnmounted, ref } from "vue";
+
+const props = withDefaults(
+  defineProps<{
+    options?: Record<string, any>;
+  }>(),
+  { options: () => ({}) }
+);
+
+const observer = ref<IntersectionObserver>();
+const observed = ref<HTMLElement>();
+const emit = defineEmits(["intersect"]);
+
+onMounted(() => {
+  observer.value = new IntersectionObserver(([entry]) => {
+    if (entry && entry.isIntersecting) {
+      emit("intersect");
+    }
+  }, props.options);
+
+  if (observed.value) {
+    observer.value.observe(observed.value);
+  }
+});
+
+onUnmounted(() => {
+  observer.value?.disconnect();
+});
+</script>