feat: add img zoom

.vitepress/theme/useMediumZoom.js

@@ -0,0 +1,24 @@
+import mediumZoom from 'medium-zoom'
+import { inject, nextTick, onMounted, watch } from 'vue'
+
+export const mediumZoomSymbol = Symbol('mediumZoom')
+
+export function useMediumZoom() {
+  return onMounted(() => inject(mediumZoomSymbol)?.refresh())
+}
+
+export function createMediumZoomProvider(app, router) {
+  if (import.meta.env.SSR)
+    return
+  const zoom = mediumZoom()
+  zoom.refresh = () => {
+    zoom.detach()
+    zoom.attach(':not(a) > img:not(.no-zoom)')
+    zoom.update({ background: 'var(--vp-c-bg)' })
+  }
+  app.provide(mediumZoomSymbol, zoom)
+  watch(
+    () => router.route.path,
+    () => nextTick(() => zoom.refresh()),
+  )
+}