LGTM, but because there is an empty line after `**database.hook_dir**`
that section has different indentation than others in the generated
manpage. Might as well fix that too. See snippet below, from a rendered
manpage on my machine.

Hannu

---
       database.backup_dir
              Directory to store tag dumps when upgrading database.

              History: this configuration value was  introduced  in
              notmuch 0.32.

              Default:  A  sibling directory of the Xapian database
              called backups.

       database.hook_dir
          Directory containing hooks run by notmuch  commands.  See
          notmuch-hooks(5).

          History:  this configuration value was introduced in not???
          much 0.32.

          Default: See HOOKS, below.