Incomplete sentence in Electron.ts documentation

[samreid]

From #103, we observed this code

faradays-electromagnetic-lab/js/common/model/Electron.ts

Lines 152 to 156 in c95a7b7

	// Evaluate the quadratic to determine the electron's position relative to the segment.
	// Use a different reusable Vector2 each time that curve.evaluate is called, so that
	const coilSegment = this.coilSegments[ this.coilSegmentIndex ];
	const returnValue = ( this.position === this.reusablePosition1 ) ? this.reusablePosition2 : this.reusablePosition1;
	this.position = coilSegment.evaluate( this.coilSegmentPosition, returnValue );

which has an incomplete sentence in the documentation.

[samreid]

Note we subsequently identified a better approach in #141. After implementing #141, nothing more should be needed here.

[pixelzoom]

I fixed the comment anyway. I'll have a look at #141.