Unable to edit markdown cells

[YorkZ]

Steps:

1. Open a .ipnb file
2. Press 'C-c C-o' to open it in ein
3. Move point to a markdown cell
4. Press C-c '
5. Got the error:

   Wrong type argument: commandp, ein:markdown-edit-code-block

I installed ein from straight.el. I also went into the ein source code and searched ein:markdown-edit-code-block, while I did see:

(define-key map (kbd "C-c '") 'ein:markdown-edit-code-block)

I wasn't able to find the definition for this function.

This is my first time using ein and therefore not sure what I'm missing.

[serycjon]

The command was removed in commit https://github.com/millejoh/emacs-ipython-notebook/commit/b478940c9fc9f66e11db47349f49a1efd8247118 . The commit message does not exactly help with understanding what happened back then.