scripts to build PageSpeed Optimization Libraries with Docker

Please see apache/incubator-pagespeed-ngx#1760 (comment)

This project is part of https://deb.myguard.nl/nginx-modules/

Please note, PAGESPEED is ABANDONED. I don't recommend to implement it if you are not using it already. There are other alternatives. The goal of this project is to keep pagespeed working as long as possible for existing installs on modern software, but there will be an end to this effort sometime.
The official documentation site is down, so I opened a new one on https://pagespeed.myguard.nl/

Pull requests are welcome.