maint: ungoofy the header at intermediate widths

[sneakers-the-rat]

i had raised this with upstream here: pydata/pydata-sphinx-theme#1784

but it's stalled because 🤷

currently at intermediate widths pydata-sphinx-theme does this whacky thing:

so this PR:

[tkoyama010]

LGTM

[lwasser]

@sneakers-the-rat are you willing to submit this to our theme instead?
we can merge this here, but ideally, we will use the theme very soon for all things guidebooks. Then we only update sphinx theme things in one place 🎉

This seems like a fix we want on the theme for our guide books. please let me know if you agree or not!! and thank you for this.

https://github.com/pyOpenSci/pyos-sphinx-theme/issues

[lwasser]

so we can totally merge here but it would be better served in the theme!!

[lwasser]

all looks good! let's merge 🚀 thank you Jonny!!!

[sneakers-the-rat]

oh and also i would be happy to pull it over there too, i did take a look at it bc i thought i remembered you mentioning it, but didn't see it used here yet which is why i pulled it here

[lwasser]

@sneakers-the-rat thank you. that was a perfect decision!

I see your pr over there now. i left a question about how this works with sphinx. ✨