Split into modules (#50)

home-manager/modules/emacs.nix

@@ -0,0 +1,14 @@
+{pkgs, ...}: {
+  programs.emacs = {
+    enable = true;
+    package = pkgs.emacs;
+    extraPackages = epkgs: [epkgs.evil];
+    extraConfig = ''
+      (load-file (let ((coding-system-for-read 'utf-8))
+                 (shell-command-to-string "agda-mode locate")))
+      (require 'evil)
+      (evil-mode 1)
+      (evil-set-undo-system 'undo-redo)
+    '';
+  };
+}