Move move .emacs.d out of configs/shared

Moving all of my Emacs-related files into their own directory at the root of
this repository.

emacs/.emacs.d/wpc/wpc-package.el

@@ -0,0 +1,27 @@
+;;; package.el --- My package configuration -*- lexical-binding: t -*-
+;; Author: William Carroll <wpcarro@gmail.com>
+
+;;; Commentary:
+;; This module hosts all of the settings required to work with ELPA,
+;; MELPA, QUELPA, and co.
+
+;;; Code:
+
+(require 'package)
+
+;; Even though we're packaging our Emacs with Nix, having MELPA registered is
+;; helpful to ad-hoc test out packages before declaratively adding them to
+;; emacs/default.nix.
+(add-to-list 'package-archives '("melpa" . "http://melpa.org/packages/"))
+(package-initialize)
+
+(unless (package-installed-p 'use-package)
+  ;; TODO: Consider removing this to improve initialization speed.
+  (package-refresh-contents)
+  (package-install 'use-package))
+(eval-when-compile
+  (require 'use-package))
+(use-package general)
+
+(provide 'wpc-package)
+;;; wpc-package.el ends here