Update options to accept a user-defined assets route.

index.js

@@ -8,7 +8,8 @@ export default async (express, options)=>{
     let opts = {
         production: true,
         routesDir: "routes",
-        assetsDir: "assets"
+        assetsDir: "assets",
+        assetsRoute: "/assets"
     };
     Object.assign(opts, options)
 
@@ -19,7 +20,7 @@ export default async (express, options)=>{
     await fs.rm(path.join(process.cwd(), ".build/"), {recursive: true, force: true});
     let root = path.join(process.cwd(), opts.routesDir);
     await addRoute(root, root, app, opts);
-    app.use(`/${opts.assetsDir}`, express.static(opts.assetsDir));
+    app.use(assetsRoute, express.static(opts.assetsDir));
 
     console.timeEnd("Build time");
     return app;