Start working on the help section with the shortdoc library

README.org

@@ -548,9 +548,62 @@ the contents of packages and allows to update packages to the latest version.
     (package-install-selected-packages))
 #+end_src
 
-* [[info:dir#Top][Info documentation]]
+* [[info:emacs#Help][Help (info)]]
 :PROPERTIES:
-:CUSTOM_ID: sec:info-documentation
+:CUSTOM_ID: sec:help
+:END:
+
+Table [[tab:help-key-bindings]] lists a number of key bindings to start playing with
+the help facilities of Emacs.
+
+#+attr_latex: :booktabs yes :float table
+#+caption[Help key bindings]:
+#+caption: Help key bindings.
+#+name: tab:help-key-bindings
+|--------------------------------+------------------+------------|
+| command                        | keys             | key map    |
+|--------------------------------+------------------+------------|
+| =Info-goto-emacs-command-node= | {{{kbd(C-h F)}}} | =help-map= |
+| =describe-function=            | {{{kbd(C-h f)}}} | =help-map= |
+| =describe-key=                 | {{{kbd(C-h k)}}} | =help-map= |
+| =describe-symbol=              | {{{kbd(C-h o)}}} | =help-map= |
+| =describe-variable=            | {{{kbd(C-h v)}}} | =help-map= |
+| =info=                         | {{{kbd(C-h i)}}} | =help-map= |
+|--------------------------------+------------------+------------|
+
+** [[info:emacs#Name Help][Shortdoc-display-group (info)]]
+:PROPERTIES:
+:CUSTOM_ID: sec:shortdoc-display-group
+:END:
+
+Listing [[lst:configure-shortdoc]] binds {{{kbd(C-h y)}}} to
+=short-doc-display-group= and defines a short documentation group for functions
+defined in this Org file.
+
+#+caption[Configure =shortdoc=]:
+#+caption: Configure =shortdoc=.
+#+name: lst:configure-shortdoc
+#+begin_src emacs-lisp
+  (when (fboundp 'shortdoc-display-group)
+    (define-key help-map (kbd "y") #'shortdoc-display-group)
+    (with-eval-after-load 'shortdoc
+      ;; Ensure defining the functions before documenting them.
+      (define-short-documentation-group init
+        "Face"
+        (invert-default-face
+         :no-manual t)
+        (set-default-face-height
+         :no-manual t)
+        "Org"
+        (org-electric-dollar
+         :no-manual t)
+        (org-syntax-convert-keyword-case-to-lower
+         :no-manual t))))
+#+end_src
+
+** [[info:info#Top][Info (info)]]
+:PROPERTIES:
+:CUSTOM_ID: sec:help
 :END:
 
 Listing [[lst:configure-info]] adds a path in my home directory to the places where
@@ -572,9 +625,9 @@ Listing [[lst:configure-info]] adds a path in my home directory to the places wh
 :END:
 
 #+attr_latex: :booktabs yes :float table
-#+caption[Basic Emacs key bindings]:
-#+caption: Basic Emacs key-bindings.
-#+name: tab:basic-emacs-key-bindings
+#+caption[Basic key bindings]:
+#+caption: Basic key bindings.
+#+name: tab:basic-key-bindings
 |----------------------+------------------------+--------------|
 | command              | keys                   | key map      |
 |----------------------+------------------------+--------------|
@@ -1392,7 +1445,7 @@ backward compatibility. See table [[tab:org-latex-class-tag-placeholder]] and ty
 #+caption: Configure =org-mode-map=.
 #+name: lst:configure-org-mode-map
 #+begin_src emacs-lisp
-  (with-eval-after-load 'org
+  (with-eval-after-load 'emacs
     ;; From: "Nicolas Richard" <theonewiththeevillook@yahoo.fr>
     ;; Date: Fri, 08 Mar 2013 16:23:02 +0100	[thread overview]
     ;; Message-ID: <87vc913oh5.fsf@yahoo.fr> (raw)
@@ -1407,8 +1460,9 @@ backward compatibility. See table [[tab:org-latex-class-tag-placeholder]] and ty
         (insert "\\(\\)")
         (backward-char 2)))
 
+    (with-eval-after-load 'org
       (define-key org-mode-map (kbd "$") #'org-electric-dollar)
-    (define-key org-mode-map (kbd "M-q") #'org-fill-paragraph))
+      (define-key org-mode-map (kbd "M-q") #'org-fill-paragraph)))
 #+end_src
 
 #+caption[Customize =org-export=]:
@@ -1734,10 +1788,12 @@ variables in order to export the =info-org-link= types in this document to
 #+caption: Convert upper to lower case keywords.
 #+name: lst:convert-upper-to-lower-case-keywords
 #+begin_src emacs-lisp
-  (with-eval-after-load 'org
+  (with-eval-after-load 'emacs
+    ;; https://tecosaur.github.io/emacs-config/#translate-capital-keywords
     (defun org-syntax-convert-keyword-case-to-lower ()
       "Convert all #+KEYWORDS to #+keywords."
       (interactive)
+      (when (derived-mode-p 'org-mode)
         (save-excursion
           (goto-char (point-min))
           (let ((count 0)
@@ -1746,7 +1802,7 @@ variables in order to export the =info-org-link= types in this document to
               (unless (s-matches-p "RESULTS" (match-string 0))
                 (replace-match (downcase (match-string 0)) t)
                 (setq count (1+ count))))
-          (message "Replaced %d keywords" count)))))
+            (message "Replaced %d keywords" count))))))
 #+end_src
 
 *** [[https://lists.gnu.org/archive/html/emacs-orgmode/2016-07/msg00394.html][Evaluate specific source blocks at load-time]]