Providing additional information with C-h f

[Heime via Users list for the GNU Emacs text editor <help-gnu-emacs@gnu.org>]

Have changed the value of companiol-navaid-level to 3, hoping that the documentation 
of the function companiol-launch will update.  But it does not.  

The documentation is evaluated once when the function is defined, and not dynamically 
when companiol-navaid-level changes.  Is there some other way to do this?  To provide 
more information about a function according to the desire of the user?

Perhaps one can include a link in the documentation string to show more information about
the function, or something similar.

(defun companiol-update-doc ()
  "Update the documentation string of `companiol-launch` dynamically."

  (let ( (doc (concat
              "Launch company-mode globally."
              (when (>= companiol-navaid-level 1)
                (concat "\n\n" companiol-dlvsec))
              (when (>= companiol-navaid-level 2)
                (concat "\n\n" companiol-dlvtri))
              (when (>= companiol-navaid-level 3)
                (concat "\n\n" companiol-dlvqtr)))) )

    (put 'paharganj-company-launch 'function-documentation doc)))

(defun companiol-launch (actm-seqr)
  "Launch company-mode globally."

  (companiol-update-doc))