I didn't look through all of them but, the folks managing bootstrap are a lot more current than just HTML and CSS.

That said, most code is easily "massaged" to use links, iframes, videos, or database information.

For instance, with the Four column footer, most of the Contact items are already ZC variables in the database.
Code:
<div class="col-md-3 col-lg-3 col-xl-3 mx-auto mt-3">            <h6 class="text-uppercase mb-4 font-weight-bold">
              Company name
            </h6>
            <p>
              Here you can use rows and columns to organize your footer
              content. Lorem ipsum dolor sit amet, consectetur adipisicing
              elit.
            </p>
          </div>
could be changed to
Code:
<div class="col-md-3 col-lg-3 col-xl-3 mx-auto mt-3">            <h6 class="text-uppercase mb-4 font-weight-bold">
              <?php
              echo $STORE_NAME;
              ?>
            </h6>
            <p>
              Here you can use rows and columns to organize your footer
              content. Lorem ipsum dolor sit amet, consectetur adipisicing
              elit.
            </p>
          </div>