nixos/installation-cd-minimal: include HTML doc

Although we don't really need HTML documentation in the minimal installer,
not including it may cause annoying cache misses in the case of the NixOS manual.

Changed files
+4
nixos
modules
installer
+4
nixos/modules/installer/cd-dvd/installation-cd-minimal.nix
···
documentation.man.enable = lib.mkOverride 500 true;
+
# Although we don't really need HTML documentation in the minimal installer,
+
# not including it may cause annoying cache misses in the case of the NixOS manual.
+
documentation.doc.enable = lib.mkOverride 500 true;
+
fonts.fontconfig.enable = lib.mkForce false;
isoImage.edition = lib.mkForce "minimal";