Add a "Last modified" date on glossary page and not only per row

[NekoJonez]

I think it would be handy to see if there is an update if you have above or underneath a locale glossary a date when it's last editted.
Otherwise, you will have to scroll through the whole list.

[pedromendonca]

Hi,
Currently, GlotPress already [has sortable columns] (​https://github.com/GlotPress/GlotPress/pull/1426) on the glossary table.
When the [Last Modified column was added] (​https://github.com/GlotPress/GlotPress/pull/1428/), it included the sortable property so it's easy to click on the Last Modified column header to sort by date and see the oldest/newer.

Still, column sorting isn't available on w.org yet.

If the column sorting isn't enough and something more is to be added, it might be useful to open this on the GlotPress issues instead of just for translate.wp.org.

[Amieiro]

Currently, at ​translate.wordpress.org you can order the glossary rows by the "Last modified" column (see image above), so you can see the last modified rows.

This template comes from GlotPress, so if you still need this update (I think it is enought with this sortable column), please, add a new issue in the ​GlotPress repo. Thank you.