use reactive breakpoints to conditionally render right sidebar

+ use reactive content div width to remove big img on album page header

src/stores/content-width.ts

@@ -0,0 +1,11 @@
+import { computed } from "vue";
+import { ref } from "@vue/reactivity";
+
+const content_width = ref(0);
+
+const isSmall = computed(() => {
+  return content_width.value < 700;
+});
+
+console.log(content_width);
+export { content_width, isSmall };