I would normally be able to do this myself by merely adding:
(global-set-key (kbd "C-a") 'select-all)
~/.emacs file but
select-all isn't the command for the "Select All" option in the Edit menu (which selects all text in the current buffer). I have tried searching for "select" in the list of commands via pressing Ctrl-h-a and typing "select", but that did not return any result with "Select all" in its description. Any ideas? If it at all relevant I am using the experimental 25.1.90 release (the one tagged in the
emacs-mirror/emacs GitHub repository) of GNU Emacs.