Split out hm/common

I went nuclear...

hm/shell/default.nix

@@ -0,0 +1,38 @@
+{ pkgs, lib, config, ... }:
+let
+  cfg = config.programs.bash;
+in
+{
+  config = {
+    programs = {
+      bash = {
+        enable = true;
+        bashrcExtra = ''
+          shopt -s expand_aliases
+          shopt -s histappend
+        '';
+        historySize = 100000;
+        historyFile = "${config.xdg.stateHome}/shell_history";
+        historyFileSize = 100000;
+        # TODO Check out Atuin
+        historyControl = [ "erasedups" "ignoredups" "ignorespace" ];
+      };
+      zsh = {
+        enable = true;
+        enableAutosuggestions = true;
+        enableCompletion = true;
+        syntaxHighlighting.enable = true;
+        historySubstringSearch.enable = true;
+        initExtra = builtins.readFile ./zshrc.sh;
+        defaultKeymap = "viins";
+        history = {
+          size = cfg.historySize;
+          save = cfg.historyFileSize;
+          path = cfg.historyFile;
+          expireDuplicatesFirst = true;
+        };
+        shellAliases = cfg.shellAliases;
+      };
+    };
+  };
+}