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.
Fix errors that were introduced into the rcirc and slack layers by
commit fea035f413.
Change the header for the slack layer's funcs.el to refer to the correct
layer.
Change the custom layout definition for rcirc to use the correct name
and binding for the layout and the correct invocation for rcirc.