Changes for PHP 8.0

[nileshgr]

I upgraded my server to PHP 8.0 and this plugin broke, some changes I made to get it working on PHP 8.0.

[idc77]

There is more than 1 implode function to fix in utils/crayon_util.class.php

[nileshgr]

@idc77 updated, but only if @aramk will merge it... this PR is sitting here since almost 10 months now

[idc77]

I know, I forked it and merged all the PRs at that date. It's now at https://git.icod.de/dalu/crayon-syntax-highlighter
See blog post: https://blog.icod.de/2021/11/29/crayon-syntax-highlighter-updated-for-php-8/
I'm aware commit history is chaotic. There was an error of everything after "Languages" in settings erroring out and I had to git pull new changes to test live.
Also removed links because they're outdated and this plugin is no longer maintained.
Especially asking for donations when it's not maintained is rude, so I removed that as well.