OCORE-83: Fixing accessibility errors in the HTML file

[DemeSzabolcs]

This is a fix for the accessibility errors in the index.html file. Below you can see the accessibility errors:

Asserting the accessibility analysis result failed. Check the accessibility report failure dump for details.
-------- Shouldly.ShouldAssertException : axeResult.Violations
    should be empty but had
1
    item and was
[Selenium.Axe.AxeResultItem (66331987)]

Additional Info:
Links must have discernible text: 
    <a class="btn btn-dark btn-social mx-2" href="<https://www.twitter.com/@">>
                        <i class="fab fa-twitter"></i>
                    </a>
    <a class="btn btn-dark btn-social mx-2" href="<https://www.facebook.com/@">>
                        <i class="fab fa-facebook"></i>
                    </a>
    <a class="btn btn-dark btn-social mx-2" href="<https://www.linkedin.com/in/@">>
                        <i class="fab fa-linkedin"></i>
                    </a>
    <a class="btn btn-dark btn-social mx-2" href="<https://www.twitter.com/@">>
                        <i class="fab fa-twitter"></i>
                    </a>
    <a class="btn btn-dark btn-social mx-2" href="<https://www.facebook.com/@">>
                        <i class="fab fa-facebook"></i>
                    </a>
    <a class="btn btn-dark btn-social mx-2" href="<https://www.linkedin.com/in/@">>
                        <i class="fab fa-linkedin"></i>
                    </a>
    <a class="btn btn-dark btn-social mx-2" href="<https://www.twitter.com/@">>
                        <i class="fab fa-twitter"></i>
                    </a>
    <a class="btn btn-dark btn-social mx-2" href="<https://www.facebook.com/@">>
                        <i class="fab fa-facebook"></i>
                    </a>
    <a class="btn btn-dark btn-social mx-2" href="<https://www.linkedin.com/in/@">>
                        <i class="fab fa-linkedin"></i>
                    </a>
    <a href="#">
                    <img class="img-fluid img-brand d-block mx-auto" src="/media/logos/microsoft.svg" alt="">
                </a>
    <a href="#">
                    <img class="img-fluid img-brand d-block mx-auto" src="/media/logos/google.svg" alt="">
                </a>
    <a href="#">
                    <img class="img-fluid img-brand d-block mx-auto" src="/media/logos/facebook.svg" alt="">
                </a>
    <a href="#">
                    <img class="img-fluid img-brand d-block mx-auto" src="/media/logos/ibm.svg" alt="">
                </a>
    <a class="btn btn-dark btn-social mx-2" href="#!"><i class="fab fa-twitter" aria-hidden="true"></i></a>
    <a class="btn btn-dark btn-social mx-2" href="#!"><i class="fab fa-facebook-f" aria-hidden="true"></i></a>
    <a class="btn btn-dark btn-social mx-2" href="#!"><i class="fab fa-linkedin-in" aria-hidden="true"></i></a>

Also, there are elements with insufficient color contrasts, but I didn't include those errors since I didn't fix them. For those see: #322

[davidtmiller]

Just getting around to some updates here, thanks for this contribution!