feat: add fuzzy matching sorter experimentally

[delphinus]

Fix #165

---

This PR adds new sorters to match “fuzzily”.

telescope.setup {
  extensions = {
    frecency = {
      matcher = "fuzzy"  --> "default"|"fuzzy"
      scoring_function = function(recency, fzy_score)
        return (10 / (recency == 0 and 1 or recency)) - 1 / fzy_score
      end,
      -- ↑This is the default value.
    },
  },
}

• default: use substr matcher. (default)
• fuzzy: calculate ordering scores with recency scores and fuzzy matched ones.

fuzzy is the one you probably think it as “fuzzy”. The logic is from telescope.nvim's fzy logic (lua/telescope/algos/fzy.lua).

A newly added scoring_function will be used to customize the balance between recency scores and fzy ones.

---

Edited. I deleted fuzzy_full and add logic to calculate scores with recency scores and fzy scores.

[delphinus]

It seems to work well in my dog-fooding. I merged this and it has closed #165, but feel free to reopen #165 and discuss again.