Remove TechPost from docs.automotivelinux.org

Thanks!

Done on all repos (docs-agl/master and docs-webtemplate/master*):

• https://github.com/automotive-grade-linux/docs-agl/commit/81cb571d66f661255d497c5da5a2d31cf5ec9a96

• https://github.com/automotive-grade-linux/docs-webtemplate/commit/32537e84454101bb99324aa546ffec8ece8050b5

• https://github.com/automotive-grade-linux/docs-webtemplate/commit/3edb214fc37aa16f9f65c4c3dfff85774f62efe1