Add git config and initial emacs config.

nix/configuration/roles/git/default.nix

@@ -0,0 +1,15 @@
+{ config, lib, pkgs, ... }:
+
+{
+  imports = [];
+
+  environment.systemPackages = with pkgs; [
+    git
+  ];
+
+  home-manager.users.talexander = { pkgs, ... }: {
+    home.file.".gitconfig" = {
+      source = ./files/gitconfig_home;
+    };
+  };
+}

nix/configuration/roles/git/files/gitconfig_home

@@ -0,0 +1,35 @@
+[user]
+	email = tom@fizz.buzz
+	name = Tom Alexander
+	signingkey = D3A179C9A53C0EDE
+[push]
+	default = simple
+[alias]
+	lg = log --color --graph --pretty=format:'%Cred%h%Creset -%C(yellow)%d%Creset %s %Cgreen(%cr) %C(bold blue)<%an>%Creset' --abbrev-commit
+	bh = log --oneline --branches=* --remotes=* --graph --decorate
+	amend = commit --amend --no-edit
+[core]
+	excludesfile = ~/.gitignore_global
+[commit]
+	gpgsign = true
+[pull]
+	rebase = true
+[log]
+	date = local
+[init]
+	defaultBranch = main
+
+# Use meld for `git difftool` and `git mergetool`
+[diff]
+	tool = meld
+[difftool]
+	prompt = false
+[difftool "meld"]
+	cmd = meld "$LOCAL" "$REMOTE"
+[merge]
+	tool = meld
+[mergetool "meld"]
+        # Make the middle pane start with partially-merged contents:
+	cmd = meld "$LOCAL" "$MERGED" "$REMOTE" --output "$MERGED"
+        # Make the middle pane start without any merge progress:
+	# cmd = meld "$LOCAL" "$BASE" "$REMOTE" --output "$MERGED"