feat(clue): allow mode arrays for clues and triggers

[pkazmier]

• I have read CONTRIBUTING.md
• I have read CODE_OF_CONDUCT.md

Allow arrays to be used to define the modes for clues and triggers.

For example, these two configurations are equivalent:

require("mini.clue").setup({
  clues = { 
    { mode = { "n", "x" }, keys = "<Leader>g", desc = "+Git" },
  },
  triggers = {
    { mode = { "n", "x" }, keys = "<Leader>" },
  },
})

require("mini.clue").setup({
  clues = { 
    { mode = "n", keys = "<Leader>g", desc = "+Git" },
    { mode = "x", keys = "<Leader>g", desc = "+Git" },
  },
  triggers = {
    { mode = "n", keys = "<Leader>" },
    { mode = "x", keys = "<Leader>" },
  },
})

[echasnovski]

Thanks for the PR!

The code looks reasonable. Would you mind also updating the H.is_trigger and H.is_clue helper? On top of tests and documentation, of course :)

[echasnovski]

Outside of commented nit picks, this looks very clean. Thanks for the attention to details in docs!

Could you also add a 'CHANGELOG.md' entry? Don't forget to mention yourself and this PR similarly to how it was done in the past.

[echasnovski]

Thanks for the work!

There are very minor nit picks that I'll address in a separate branch.