fix viewer endpoint route url (#642)

* fix viewer endpoint route url

* fix viewer endpoint route url
ufo

* code style

* chore: might be optional

---------

Co-authored-by: Mariusz Kuś <mariusz.kus@meble.pl>
Co-authored-by: Sébastien Chopin <seb@nuxt.com>

src/module.ts

@@ -255,10 +255,10 @@ export default defineNuxtModule<ModuleOptions>({
     // Add _tailwind config viewer endpoint
     // TODO: Fix `addServerHandler` on Nuxt 2 w/o Bridge
     if (nuxt.options.dev && moduleOptions.viewer) {
-      const route = '/_tailwind'
+      const { withTrailingSlash, withoutTrailingSlash, joinURL } = await import('ufo')
+      const route = joinURL(nuxt.options.app?.baseURL, '/_tailwind')
       // @ts-ignore
       const createServer = await import('tailwind-config-viewer/server/index.js').then(r => r.default || r) as any
-      const { withTrailingSlash, withoutTrailingSlash } = await import('ufo')
       const routerPrefix = isNuxt3() ? route : undefined
       const _viewerDevMiddleware = createServer({ tailwindConfigProvider: () => tailwindConfig, routerPrefix }).asMiddleware()
       const viewerDevMiddleware = eventHandler((event) => {