feat: refactor Vite plugin loading mechanism and improve plugin management

vite-plugins/01.unplugin-vue-markdown.ts

@@ -1,11 +1,12 @@
-import type { ConfigEnv, PluginOption } from 'vite';
 import Markdown from 'unplugin-vue-markdown/vite';
 
-export function loadPlugin(_configEnv: ConfigEnv): PluginOption {
+import type { LoadPluginFunction } from './_loadPlugins';
+
+export const loadPlugin: LoadPluginFunction = (_pluginLoadOptions) => {
   return [
     // https://github.com/unplugin/unplugin-vue-markdown
     Markdown({
       headEnabled: true,
     }),
   ];
-}
+};