add: locale and i18n

src/middleware.ts

@@ -0,0 +1,12 @@
+import { i18nRouter } from 'next-i18n-router';
+import { NextRequest } from 'next/server';
+import i18nConfig from '../i18nConfig';
+
+export function middleware(request: NextRequest) {
+  return i18nRouter(request, i18nConfig);
+}
+
+// only applies this middleware to files in the app directory
+export const config = {
+  matcher: '/((?!api|static|favicon.ico|.*\\..*|_next).*)'
+};