Running emacs 25.2.2, general, evil and markdown-mode installed from MELPA.

The problem is when I hit `TAB` on a heading in a markdown file, it does not cycle visibility of content.

`C-h k TAB` shows it is assigned to `evil-jump-forward`.

So, in my `init.el`, I added:

```
(general-def 'markdown-mode-map
  "TAB" 'markdown-cycle)

```

But still `TAB` is assigned to `evil-jump-forward`.

How do I assign `TAB` to `markdown-cycle` in `markdown-mode`?

Moreover, can I assign it such that only when the cursor is on a heading, it is assigned to `markdown-cycle` but at other locations, it is assigned to `evil-jump-forward`?