feat: <Leader>fk for keymaps picker

[S1M0N38]

What do you think about adding the fk keymap to open the keymaps picker? Personally, I find it very useful to list all keymaps, especially when transitioning from other 'distros'.

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Suggested changes in plugin/20_keymaps.lua

nmap_leader('fk', '<Cmd>Pick keymaps<CR>', 'Keymaps')

[echasnovski]

Although I do understand the reasoning, it doesn't feel like a good idea long term. There is more details in #11.