Replace On/Off with just animationOff to better align with checkbox and capitalization of other menu items.

Signed-off-by: moderation <[e-mail]>

src/viewer.js

···
 		
 		const animationToggleCtrl = this.animFolder.add(this.state, 'animationPaused');
 		animationToggleCtrl.onChange((paused) => this.toggleAnimation(paused));
-		animationToggleCtrl.name('Animation On/Off');
+		animationToggleCtrl.name('animationOff');
 
 		// Morph target controls.
 		this.morphFolder = gui.addFolder('Morph Targets');