feat: big upgrade to 20.03

use emojis for i3status-rust
remove overlays
configure mail via home-manager
adapt to 20.03 config options
automatically symlink cloud directories into home

lib/default.nix

@@ -0,0 +1,7 @@
+{ pkgs, ... }:
+{
+  writeTOML = object: pkgs.runCommand "generated.toml" {} ''
+    echo '${builtins.toJSON object}' | ${pkgs.remarshal}/bin/json2toml > $out
+  '';
+  toTOML = object: builtins.readFile (pkgs.writeTOML object);
+}