Adding HPCE logo

- Add logo to index.md
- Add favicon in several sizes
- remove extraneous images
- Add PSI logo to footer

_includes/footer.html

@@ -3,7 +3,7 @@
                 <div class="col-lg-12 footer">
                &copy;{{ site.time | date: "%Y"  }} {{site.company_name}}. All rights reserved. <br />
 {% if page.last_updated %}<span>Page last updated:</span> {{page.last_updated}}<br/>{% endif %} Site last generated: {{ site.time | date: "%b %-d, %Y"  }} <br />
-<p><img src="{{ "/images/company_logo.png"}}" alt="Company logo"/></p>
+<p><img style="margin-top: 1em;" src="{{ "/images/psi-logo.png"}}" alt="PSI logo"/></p>
                 </div>
             </div>
 </footer>

_includes/head.html

@@ -29,7 +29,9 @@
 <script src="{{ "/js/toc.js"}}"></script>
 <script src="{{ "/js/customscripts.js"}}"></script>
 
-<link rel="shortcut icon" href="{{ "/images/favicon.ico"}}">
+<link rel="apple-touch-icon" sizes="180x180" href="/apple-touch-icon.png">
+<link rel="icon" type="image/png" sizes="32x32" href="/favicon-32x32.png">
+<link rel="icon" type="image/png" sizes="16x16" href="/favicon-16x16.png">
 
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