fonts: switch to Monaspace Argon

this one is especially easy for reading code comments

hosts/common/programs/fontconfig.nix

@@ -58,8 +58,8 @@ in
         # "Font Awesome 6 Brands"
       ];
       monospace = [
-        # "Monaspace Argon"
-        # "Monaspace Neon"
+        "Monaspace Argon"  #< thin, slightly handwriting-ish
+        # "Monaspace Neon"  #< typewriter style
         "Hack Nerd Font Propo"
         # "DejaVuSansM Nerd Font Propo"
         "NotoMono Nerd Font Propo"
@@ -96,7 +96,7 @@ in
       gyre-fonts              #  4 MiB; Tex Gyre *; ttf substitutes for standard PostScript fonts
       # hack-font               #  1 MiB; Hack; also available as a NerdFonts
       liberation_ttf          # 4 MiB; Liberation {Mono,Sans,Serif}; also available as a NerdFonts
-      # monaspace               # 20 MiB;
+      monaspace               # 20 MiB;
       noto-fonts-color-emoji  # 10 Mib; Noto Color Emoji
       unifont                 # 16 MiB; Unifont; provides LOTS of unicode coverage