Spacemacs lacks a keybinding alternative to the most natural way of scrolling
Info pages (i.e. SPC) in vanilla emacs.
Anyway, this commit adds J/K to scroll most naturally through info pages.
Currently, in Info-mode, a keybinding for J is not defined while K is bound to
evil-lookup.
Issue #2828 already adresses the inconsistent experience, and in my opinion this
can and should be improved as navigating Info pages is a very crucial part of
using Emacs.
Personally I have bound J/K to scroll page up/down in buffers/pdf/djvu/doc-view,
which I inherited from using the zathura pdf reader, and I think this is a better
default than the default vim alternatives.
