Fix main logos default path (#218)

layouts/partials/navigators/navbar.html

@@ -1,5 +1,5 @@
 {{/*  default logos  */}}
-{{ $mainLogo := "/images/site/main-logo.png" }}
+{{ $mainLogo := "/images/main-logo.png" }}
 {{ $invertedLogo := "/images/inverted-logo.png" }}
 
 {{/*  if custom logo is used, them  */}}