WIP - added prototype for visually hidden descriptive spans

Story https://www.pivotaltracker.com/story/show/82381722 
Extend the labelling form header to add screen reader help text.
This code will do that, but we need to know where to place the additional data e.g. :-
    <div class='form-group title hide js-claimanttype individual'>
        <label for="claim_claimant_1_title">**<span class='visuallyhidden'>Claimant 1</span>** Title</label>
        <input class="narrow" id="claim_claimant_1_title" maxlength="8" name="claim[claimant_1][title]" size="8" type="text" />
    </div>