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

overlays/overlays.nix

@@ -1,6 +0,0 @@
-self: super:
-with super.lib;
-let
-  eval = import <nixpkgs/nixos/lib/eval-config.nix>;
-  paths = (eval {modules = [(import <nixos-config>)];}).config.nixpkgs.overlays;
-in foldl' (flip extends) (_: super) paths self

overlays/scripts.nix

@@ -1,3 +0,0 @@
-(self: super: {
-  scripts = import <niveum/packages/scripts> { pkgs = super; lib = super.lib; };
-})

overlays/toml.nix

@@ -1,6 +0,0 @@
-(self: super: {
-  writeTOML = object: super.runCommand "generated.toml" {} ''
-    echo '${builtins.toJSON object}' | ${super.remarshal}/bin/json2toml > $out
-  '';
-  toTOML = object: builtins.readFile (self.writeTOML object);
-})