Hide the insertion caret (a vertical bar on a text)

[grocio]

Let me share some info with you. One of my colleagues has noticed that a browser shows a vertical bar or insertion caret next to word stimuli. He uses Chrome on Windows 10.

Inspired by #1407, I made trials switching the insertion caret on/off.

var caret_off = {
    type: 'call-function',
    func: function() {
        document.body.style.caretColor= "transparent";
    }
};

var caret_on = {
    type: 'call-function',
    func: function() {
        document.body.style.caretColor= "auto";
    }
};

timeline.push(caret_off, trial_without_caret, caret_on, trial_with_caret);

It worked well. Hope this info would be helpful.