Apostrophes are not necessary in phrases such as 'FreeBSD's Handbook' and 'Documentation's Handbook'.
'Presentation and papers': should be plural, 'Presentations and papers'.
A few other suggested changes.
I noticed FreeBSD's Handbook at https://docs.freebsd.org/en/ a few weeks ago.
The diff here in Phabricator is taken from the beastie-theme-en branch of my fork in GitHub, https://github.com/grahamperrin/freebsd-doc/tree/beastie-theme-en.