NOTE: the `o` and `c` keymaps will continue to work. This only changes
the text labels and adds new keymaps for `y` and `n`.
* chore: replace ok and cancel with yes and no in confirmation window
* chore: allow to configure labels and keymaps for confirmation window
* chore: remove potential duplicate cancel keymaps
* chore: update README and oil.txt
* chore: nowait on confirm mappings and cleanup
* refactor: fully transition to yes/no
* move the config from under the `confirmation` key to the `preview`
key, which is already in use for customizing the window
* fully default to yes/no, keeping the o/c keybindings for backwards
compatibility
* make all of the `cancel` keybindings explicit (q, C-c, esc)
* more dynamically choose highlighting of the action labels
* refactor: just use yes/no and abandon configuration
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Co-authored-by: Steven Arcangeli <stevearc@stevearc.com>
