Use pre-generated HTML entities instead

PHP htmlentities() function somewhat doesn't encode string into entities
and there is no way to configure this behaviour the way I need.
Add an automatic deploy script payload.php

This script makes use of GitHub Hooks API. For more information, see:
https://developer.github.com/v3/repos/hooks/
Migrate from https://so.mu

This commit merges https://so.mu, my previous website, into this repository.
Some features are not merged, e.g. JS code that changed CSS stylesheet based
on current sun position.

It also includes technologies icons below my name, but I most likely will
drop them soon.