No theme switch button on mobile

[IgnatBeresnev]

Originally reported in #2347

There's no way to switch to the light/dark themes on mobile, the button is not there:

screenshot

Whereas it exists on desktop:

screenshot

[IgnatBeresnev]

Need to figure out if this is intentional and theme-switching should not be accessible on mobile, or if it was simply forgotten and then needs UI/UX design

[atyrin]

• the same for the new home page icon

[whyoleg]

Fixed by #3917 in Dokka 2.0.0