Add easing functions to particles values animations

The size, opacity and maybe other animation options could benefit an easing option, to change the animation speed accordingly to the given easing function. This could create an effect where the opacity starts fading slow accelerating in the end, the same could be for size or other animations.

Checklist

• engine/src/Utils/EasingFunctions.ts ✅ Commit ad52bfc
• engine/src/Options/Interfaces/Particles/Size/ISizeAnimation.ts ✅ Commit 122a704
• engine/src/Options/Interfaces/Particles/Opacity/IOpacityAnimation.ts ✅ Commit 452ec04
• engine/src/Updaters/SizeUpdater.ts ✅ Commit 99b1544
• engine/src/Updaters/OpacityUpdater.ts ✅ Commit fc5208a
• markdown/Options/Particles/Size.md ✅ Commit aeceee4
• markdown/Options/Particles/Opacity.md ✅ Commit 7f50afb