Fix magit and diff-hl setup

It seems that Emacs now yields a warning when loading files without lexical
binding enabled.

init.org

@@ -120,8 +120,8 @@
 
   #+end_src
 
-  I want lexical scoping for the init-file, which can be specified in the
-  header. The first line of the configuration is as follows:
+  I want lexical scoping for the init and early-init files, which can be
+  specified in the header. The first line of the configuration is as follows:
 
   #+begin_src emacs-lisp
 
@@ -129,6 +129,12 @@
 
   #+end_src
 
+  #+begin_src emacs-lisp :tangle early-init.el
+
+  ;;; -*- lexical-binding: t -*-
+
+  #+end_src
+
   The =init.el= should (after the first run) mirror the source blocks in the
  =init.org=. We can use =C-c C-v t= to run =org-babel-tangle=, which extracts
   the code blocks from the current file into a source-specific file (in this
@@ -633,25 +639,27 @@
 
 * Version control
 
-  Magit is the best.
+  [[https://magit.vc/][Magit]] is the best.
 
   #+begin_src emacs-lisp
 
   ;; A Git porcelain inside Emacs.
   (use-package magit
-    :hook ((magit-pre-refresh . diff-hl-magit-pre-refresh)
-           (magit-post-refresh . diff-hl-magit-post-refresh))
     :bind (:map custom-bindings-map ("C-c m" . magit-status)))
 
   #+end_src
 
-  Have some visual indication where there are uncommitted changes.
+  Have some visual indication where there are uncommitted changes using
+  [[https://github.com/dgutov/diff-hl][~diff-hl~]]. In addition, ~diff-hl~ can be automatically updated when interacting
+  with Magit.
 
   #+begin_src emacs-lisp
 
   ;; Highlight uncommitted changes using VC
   (use-package diff-hl
     :defer t
+    :hook ((magit-pre-refresh . diff-hl-magit-pre-refresh)
+           (magit-post-refresh . diff-hl-magit-post-refresh))
     :config
     (global-diff-hl-mode 1))