Quick gist to play around with magit-section

magit-test-section.el

;; See https://magit.vc/manual/magit-section.html

(defun magit-test-section ()
  (interactive)
  ;; create a new buffer
  (with-current-buffer (get-buffer-create "*magit-test-section*")
    ;; trigger the magit section mode
    (magit-section-mode)

    ;; deactivate the buffer read-only mode temporarily
    (let ((inhibit-read-only t))
      ;; wipe the buffer clean
      (erase-buffer)

      ;; can start inserting sections
      (magit-insert-section (magit-section "Section1")
        (magit-insert-heading (insert "Heading1"))
        (magit-insert-section-body (insert "Body1\n\n")))

      (magit-insert-section (magit-section "Section2")
        (magit-insert-heading (insert "Heading2"))
        (magit-insert-section-body (insert "Body2\n\n")))

      (magit-insert-section (magit-section "Section3")
        (magit-insert-heading (insert "Heading3"))

        ;; can nest section inside other sections
        (magit-insert-section (magit-section "Section3a")
          (magit-insert-heading (insert "Heading3a"))
          (magit-insert-section-body (insert "Body3a\n\n")))

        (magit-insert-section (magit-section "Section3b")
          (magit-insert-heading (insert "Heading3b"))
          (magit-insert-section-body (insert "Body3b\n\n")))
        )
      )
    ;; we're done editing the buffer
    ;; swith to it
    (pop-to-buffer (current-buffer))))