The script used to identify and update the change is added into the GitHub
workflows script directory. A workflow action can be created to trigger the
script to update the headers on the first of every new year. Possibly a task for
a consequent PR.
A BEGIN_SRC block in the documents had no language specified
which would break CI.
I have also changed the eldoc setup to run each time the mode is
entered instead of only in the initially loaded buffer.