No longer link to alternative implementations

The idea behind that link was to redirect users who want more features
to packages that provide more features, but that has never actually
worked.  This package seems to be the de facto default for this sort
of functionality and if something is missing, someone sooner or later
requests that it is added here.  So remove the passive-aggressive and
ineffective comment and link.

README.org

@@ -28,10 +28,6 @@ commands, then you should bind them in ~hl-todo-mode-map~, e.g.:
   (keymap-set hl-todo-mode-map "C-c i" #'hl-todo-insert)
 #+end_src
 
-See [[https://www.emacswiki.org/emacs/FixmeMode][this list]] on the Emacswiki for other packages that implement
-the same basic features, but which might also provide additional
-features that you might like, but which I don't deem necessary.
-
 See [[https://github.com/tarsius/hl-todo/wiki][FAQ and Common Issues]] if something isn't working as expected.
 
 #+html: <br><br>

hl-todo.el

@@ -44,10 +44,6 @@
 ;;   (keymap-set hl-todo-mode-map "C-c o" #'hl-todo-occur)
 ;;   (keymap-set hl-todo-mode-map "C-c i" #'hl-todo-insert)
 
-;; See [[https://www.emacswiki.org/emacs/FixmeMode][this list]] on the Emacswiki for other packages that implement
-;; the same basic features, but which might also provide additional
-;; features that you might like, but which I don't deem necessary.
-
 ;;; Code:
 
 (require 'compat)