documentation reference page has broken link to class template unordered_map

from this page https://www.boost.org/latest/libs/unordered/doc/html/unordered/ref.html
there are a bunch of links for class templates.

some of them are broken links. for example for unordered_map is a broken link, which leads to here https://www.boost.org/latest/libs/unordered/doc/html/unordered/reference/unordered_map.html/

these seems to be broken in the same way
* unordered_map
* unordered_flat_map
* unordered_node_set
* concurrent_flat_set
* concurrent_node_set

Start at the unordered reference page and inspect the links for unordered_map, unordered_flat_map, unordered_node_set, concurrent_flat_set, and concurrent_node_set, comparing their targets with the corresponding documentation pages. Done means each listed class-template link resolves without the erroneous trailing slash or another broken target.

Written by the indexing model from the issue text.