diff --git a/config.org b/config.org
index 51cca74..5617b4f 100644
--- a/config.org
+++ b/config.org
@@ -340,6 +340,7 @@ it.
 Install the package, enable it and ensure that it always is installed:
 #+BEGIN_SRC emacs-lisp
   (use-package pdf-tools
+    :ensure t
     :hook (pdf-tools-enabled . pdf-view-midnight-minor-mode)
     ;;:hook (pdf-tools-enabled . hide-mode-line-mode)
     :init
@@ -524,6 +525,18 @@ Install the package, enable it and ensure that it always is installed, and then
   ; Wrap around when suggestions reach bottom.
   (setq company-selection-wrap-around t)
 
+  (dolist (key '("<return>" "RET"))
+    ;; Here we are using an advanced feature of define-key that lets
+    ;; us pass an "extended menu item" instead of an interactive
+    ;; function. Doing this allows RET to regain its usual
+    ;; functionality when the user has not explicitly interacted with
+    ;; Company.
+    (define-key company-active-map (kbd key)
+      `(menu-item nil company-complete
+                  :filter ,(lambda (cmd)
+                             (when (company-explicit-action-p)
+                               cmd)))))
+
   ; Use tab key to cycle through suggestions.
   ; ('tng' means 'tab and go')
   (company-tng-configure-default)
@@ -593,6 +606,23 @@ Install the package, enable it and ensure that it always is installed, and then
     :init
     (elcord-mode 1))
 #+END_SRC
+** Nix Mode
+An Emacs major mode for editing Nix expressions. There is also a manual available at nix-mode.org.
+
+#+BEGIN_SRC emacs-lisp
+  (use-package nix-mode
+    :ensure t
+    :mode "\\.nix\\'")
+#+END_SRC
+
+** LUA Mode
+lua-mode is a major mode for editing Lua sources in Emacs.
+
+#+BEGIN_SRC emacs-lisp
+  (use-package lua-mode
+    :ensure t)
+#+END_SRC
+
 ** LSP Mode
 LSP mode will give you IDE capabilities in Emacs, using Microsoft's
 Universal Language Server Protocol. The same one that VSCode uses for
@@ -619,14 +649,17 @@ on how to install the Programming Language Servers that you want.
 *** Configuration
 #+BEGIN_SRC emacs-lisp
   ;; optionally
-  (use-package lsp-ui :commands lsp-ui-mode
-    :ensure t)
-  (use-package company-lsp :commands company-lsp
+  (use-package lsp-ui
+    :commands lsp-ui-mode
     :ensure t)
+  ;; (use-package company-lsp
+  ;;   :commands company-lsp
+  ;;   :ensure t)
   ;; if you are helm user
   ;;(use-package helm-lsp :commands helm-lsp-workspace-symbol)
   ;; if you are ivy user
-  (use-package lsp-ivy :commands lsp-ivy-workspace-symbol
+  (use-package lsp-ivy
+    :commands lsp-ivy-workspace-symbol
     :ensure t)
   ;;(use-package lsp-treemacs :commands lsp-treemacs-errors-list
   ;;  :ensure t)