The quick answer is to refer you to my question and answer on the same topic, about two questions ago. However, basically, there are three ways. The first you have found and you can place '@include background-grid' in the element that you wish to have a grid shown. I think you will find that you can't install grid-toggle, as directed, but I don't think you need to. The second method is the toggle. You have to place '@include grid-toggle' in your style.scss in either a * { ... } selector or an html{ ... } selector. You reference the script grid.js in the head of your web page. However, that script assumes you want the grid on your body div. You add data-development-grid="show" (or "hide") inside the body opening div.
You can put the grid on another element such as a wrap div (don't we all use wrap?), by adding data-development-grid="show" to the wrap div, but then you need to modify the grid.js file. Here is my javascript version as a guide (seems to work, but I'm no programmer!):
(function() {
window.onload = function() {
var body = document.body;
body.onkeypress = function(e) {
if (e.keyCode === 103 || e.charCode === 103) {
var wrap = document.getElementById('wrap');
var dev = wrap.getAttribute('data-development-grid');
if (dev === null || dev === 'hide') {
wrap.setAttribute('data-development-grid', 'show');
}
else {
wrap.setAttribute('data-development-grid', 'hide');
}
}
};
};
})();
BTW, your body or wrap (whichever you choose) must not have a background colour or image because the grid will be underneath and therefore invisible.
The third method is the overlay, which I particularly like because it sits over the background colour. for this, add @include grid-overlay('#wrap'); to the *{ ...} or html{ ... } element in your style.scss file. You will get a 4-line symbol in the bottom left and when you mouseover it, it causes the grid to appear - mouseoff = disappear.
I've assumed that you want the grid in a wrap div, but you can put it where you like.
I hope this helps.