Custom Main Menu Tweaks

Adds four new properties to Custom Main Menu's buttons:

• "anchor" : "start" for left justified text, "middle" for centered text, and "end" for right justified text
• "hoverTextOffsetX" : Horizontal text offset for when a button is hovered over
• "hoverTextOffsetY" : Same as above but vertical
• "offsetAnimationFrames": Controls how long it takes for maximum text offset to be reached, lower numbers being faster