This caused no effect for the first call to ToggleHiddenAll().
The second call works as value was set correctly inside
ToggleHiddenAll() on the first call.
Vimwiki is not config but it's data so ".local/share/nvim" is
more proper location for it.
Here relative path was given so it tries to create new vimwiki
folder when launched from other than home dir or changing current
dir using `:cd <path>` inside vim when launching vimwiki.