Merge branch 'master' into development

* master:
  added information about installation on Gentoo

README.md

@@ -90,6 +90,10 @@ Most Linux and BSD systems can handle either [TTF][ttf_latest] or [OTF][otf_late
 
         $ pacman -S ttf-hack
 
+* *Gentoo Linux*: install the [media-fonts/hack](https://packages.gentoo.org/packages/media-fonts/hack) package from the main Portage tree:
+
+        $ emerge -av media-fonts/hack
+
 * *Fedora / CentOS*: install from [copr](https://copr.fedoraproject.org/coprs/heliocastro/hack-fonts/). For Fedora >= 23:
 
         $ dnf install dnf-plugins-core