Remove unused animation and midi pages

[Pugzy]

These modules were added as in development in June 2017 and still do not exist.

The pages have remained this way since their creation and I would hope development focus is not on animated blocks or midi support.

[AustinLMayes]

The animation module exists actually.

Animations: https://github.com/StratusNetwork/projectares/tree/master/PGM/src/main/java/tc/oc/pgm/animation

[Pugzy]

Thanks, I'll take a look at the midi module code and see if I can figure some documentation out.