emacs-configuration: Avoid failing if custom.el is missing

Also, adjust some comments.

user-config/emacs/.emacs.d/config.org

@@ -5,8 +5,6 @@
 #+PROPERTY: header-args:emacs-lisp :tangle yes :tangle-mode (identity #o444)
 #+PROPERTY: header-args:shell :tangle no
 
-#+CATEGORY: emacs
-
 * Overview
 
 This is a literate emacs configuration which leverages [[https://orgmode.org/][org-mode]].
@@ -184,7 +182,8 @@ as a TODO item.
 #+begin_src emacs-lisp
   ;; Load customization's made by customize
   (setq custom-file (no-littering-expand-var-file-name "custom.el"))
-  (load custom-file)
+  (if (file-exists-p custom-file)
+      (load custom-file))
 #+end_src
 
 * Set Language Environment
@@ -1381,7 +1380,7 @@ settings can likely be replaced by the [[https://github.com/hrs/sensible-default
   ;; Turn hl-line-mode on globally
   ;;(global-hl-line-mode)
 
-  ;; Activate linum-mode in all buffers used for programming
+  ;; Activate display-line-numbers-mode in all buffers used for programming
   (activate-mode-with-hooks (lambda () (display-line-numbers-mode 1)) code-modes)
 
   ;; Add little indicators to fringe indicating the location of point in the given window