Add note about additional configs to readme
Add note about additional configs to readme

noikiy/Benchmark-PHP-HHVM-Zephir,treffynnon/Benchmark-PHP-HHVM-Zephir,noikiy/Benchmark-PHP-HHVM-Zephir,noikiy/Benchmark-PHP-HHVM-Zephir,treffynnon/Benchmark-PHP-HHVM-Zephir,noikiy/Benchmark-PHP-HHVM-Zephir,noikiy/Benchmark-PHP-HHVM-Zephir,treffynnon/Benchmark-PHP-HHVM-Zephir,treffynnon/Benchmark-PHP-HHVM-Zephir