chore(example): accept arguments via run-script (#2115)

Author: hiroppy

examples/run-example.js

@@ -2,8 +2,9 @@
 
 const { spawn } = require('child_process');
 
+const [, , ...args] = process.argv;
 const cwd = process.env.INIT_CWD;
-spawn('node', ['../../../bin/webpack-dev-server.js'], {
+spawn('node', ['../../../bin/webpack-dev-server.js', ...args], {
   cwd,
   stdio: 'inherit',
 });