nixos/fonts: install gyre-fonts by default

gyre-fonts provides high-quality TrueType substitutes for standard PostScript
fonts. Unlike most other distributions, NixOS does not install Ghostscript and
its Type 1 fonts by default, so we must get the standard fonts elsewhere.

Changed files
+1
nixos
modules
config
fonts
+1
nixos/modules/config/fonts/fonts.nix
···
pkgs.xorg.fontbhlucidatypewriter75dpi
pkgs.dejavu_fonts
pkgs.freefont_ttf
+
pkgs.gyre-fonts # TrueType substitutes for standard PostScript fonts
pkgs.liberation_ttf
pkgs.xorg.fontbh100dpi
pkgs.xorg.fontmiscmisc