More documentation needed for ?showGuides

[zepumph]

Looks like an unfinished doc:

geometric-optics/js/common/GeometricOpticsQueryParameters.js

Lines 24 to 30 in f530833

	// show the guides on the
	showGuides: {
	type: 'boolean',
	defaultValue: true,
	public: true
	}

[zepumph]

#154

[veillette]

The documentation was added to make it clear that show guides refer to the checkbox guides rather than guides themselves.

Assigning back to @zepumph for review.