Use '<shift-k>' as default hover mapping

[asadzman]

Is your feature request related to a problem? Please describe.
Vscodevim default gh mapping to hover doesn't make sense. In both vim and neovim K is used as keywordprg.

Describe the solution you'd like
Change plugin default to have K perform hover

Describe alternatives you've considered
I can add the setting myself

    {
      "before": [
        "K"
      ],
      "commands": [
        "editor.action.showHover"
      ]
    },

But this makes no sense to not include this by default. When both nvim and vim support this and K in vsvim does nothing.

Additional context
Related #9995