ARIA update in shortcode outputs

[guneetnarula]

1. For style=announcements, link inside
2. element should have aria-label="announcement, date-and-month-of-publishing, title-of-post". And the date should also be a link.

Example HTML output of list element:
<li><a class="title" href="../announcements/overview-of-dsroi-2021/" role="link" aria-label="announcement, 17th August, overview of DSROI 2021"><span class="announcement-date">17 Aug '21:</span> Overview of DSROI 2021</a></li>

2. For style=modules, title should also link to the module, but text color should remain black. And the open button should have the aria-label="open week 1 module"