Factor out Go setup into its own section

README.org

@@ -376,8 +376,6 @@ the contents of packages and allows to update packages to the latest version.
 #+begin_src emacs-lisp -n :results silent
 (when (require 'treesit nil 'noerror)
   (setopt
-   ;; Set `tab-width' in `after-change-major-mode-hook' function too.
-   go-ts-mode-indent-offset 2
    treesit-language-source-alist
    '((bash "https://github.com/tree-sitter/tree-sitter-bash" "master" "src")
      (c "https://github.com/tree-sitter/tree-sitter-c" "master" "src")
@@ -407,13 +405,7 @@ the contents of packages and allows to update packages to the latest version.
           "master" "tsx/src")
      (typescript "https://github.com/tree-sitter/tree-sitter-typescript"
                  "master" "typescript/src")
-     (yaml "https://github.com/ikatyang/tree-sitter-yaml" "master" "src")))
-
-  (add-hook 'after-change-major-mode-hook
-            (defun on-go-ts-mode-hook ()
-              (when (derived-mode-p 'go-ts-mode 'go-mod-ts-mode)
-                (setq-local tab-width 2))))
-  (add-to-list 'auto-mode-alist `(,(rx ".go" eos) . go-ts-mode)))
+     (yaml "https://github.com/ikatyang/tree-sitter-yaml" "master" "src"))))
 #+end_src
 
 * [[info:emacs#Faces][Text faces or styles (info)]]
@@ -4667,6 +4659,20 @@ byte code:
 
 1. [[https://gobyexample.com/][Go by example]]
 
+#+caption[Setup Go programming]:
+#+caption: Setup Go programming.
+#+name: lst:setup-go
+#+begin_src emacs-lisp -n
+(when (featurep 'treesit)
+  ;; Set `tab-width' in `after-change-major-mode-hook' function too.
+  (setopt go-ts-mode-indent-offset 2)
+  (add-hook 'after-change-major-mode-hook
+            (defun on-go-ts-mode-hook ()
+              (when (derived-mode-p 'go-ts-mode 'go-mod-ts-mode)
+                (setq-local tab-width 2))))
+  (add-to-list 'auto-mode-alist `(,(rx ".go" eos) . go-ts-mode)))
+#+end_src
+
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