Since 56b2970 has proven to be a no-go for us, as it breaks existing
links, let's embrace the trailing slash and use absolute links
everywhere for our pages. This way we'll get around browser cleverly
appending the relative link to the current location (since it ends with
a slash), and given our docs/ layout is flat it's not much of a hassle
either.
Converted using this beauty:
$ sed -ri 's/(\[.+\]\()([A-Z_]+\))/\1\/\2/g' *.md
Resolves: #32088 (again) and #32310
This reverts commit 5e8ff010a1.
This broke all the URLs, we can't have that. (And actually, we probably don't
_want_ to make the change either. It's nicer to have all the pages in one
directory, so one doesn't have to figure out to which collection the page
belongs.)
