feat(site): centred home logo that docks on scroll, slashed nav underline, square defocused hero event

site/index.php

@@ -2,6 +2,7 @@
 // One-page site: Home + Equipa + Modalidades + Horário + Contactos.
 // CrossFit is a separate page (site/crossfit.php).
 $current_uri_2 = '';
+$nav_center_logo = true;   // big centred logo over the hero, docks left on scroll (navbar.php)
 
 // No gym in the URL (/, /home, old links): send people to a gym page. With a
 // single published gym that is a 301 to it (query string kept, e.g.