Modify meson build to install man page

4 jobs for add/man in 3 minutes and 33 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Test
passed #236615
ubuntu-16.04

00:03:33

passed #236616
ubuntu-17.10

00:03:32

passed #236617
ubuntu-18.04

00:03:01

passed #236618
ubuntu-18.04-no-backend

00:03:12