The radio button and checkbox examples should show how to create accessible group names

[dylanb]

The current examples for radio button and checkbox groupings do not show how to create accessible group labels.

Ideally, the radio button would not allow you to create it without a group label (because this is always an accessibility problem), however, in lieu of that, we should show these examples ONLY with group labels and also document the accessibility requirement for them.

Radio button example markup can be changed to the following

<form>
    <fieldset>
        <legend>Group Name</legend>
        <div id="radio">
            <input type="radio" id="radio1" name="radio" /><label for="radio1">Choice 1</label>
            <input type="radio" id="radio2" name="radio" checked="checked" /><label for="radio2">Choice 2</label>
            <input type="radio" id="radio3" name="radio" /><label for="radio3">Choice 3</label>
        </div>
    </fieldset>
</form>

The checkbox markup can be changed to the following

    <fieldset>
        <legend>Group Name</legend>
        <div id="format">
            <input type="checkbox" id="check1" /><label for="check1">B</label>
            <input type="checkbox" id="check2" /><label for="check2">I</label>
            <input type="checkbox" id="check3" /><label for="check3">U</label>
        </div>
    </fieldset>

[jzaefferer]

@arschmitz how is the button rewrite going to affect this?