[Ergoemacs] Missing ergoemacs-fixed-key and ergoemacs-key functions?

I want to customize few keybinding in Ergoemacs, and [this site](https://ergoemacs.github.io/customize-keys.html) tells me that I can use functions mentioned in the title to do that, however I can't find them when using \`describe-function\`. What's happening here?

That documentation seems very outdated. The changelog is from 2013 and that function was removed (according to an [issue](https://github.com/ergoemacs/ergoemacs-mode/issues/382)) before 2015. The GitHub page has a [small section on keybindings](https://github.com/ergoemacs/ergoemacs-mode#changing-your-own-bindings), maybe that's more up-to-date.