Docs nav offset

Noticed a minor visual inconsistency that can sometimes be annoying when browsing around the docs (e.g. it blocks the table of contents on the left), since the docs do not display the Support Ukraine banner, there's a redundant 60px offset for the navbar. Same applies for the Support page.

I'm willing to PR this, but should we...
a) include the support banner for the default layout as well
b) make the `.fixedHeaderContainer` class's `top: 60px` style conditional and only apply it within home's `{% include nav.html %}`