feat(live_grep): attach mapping is configurable through options

[richardmarbach]

Description

I started writing a new picker to improve the refinement of the live_grep picker search results and noticed that all I really wanted to do was add custom attachment_mappings to the existing live_grep picker. It would be nice if the attachment_mappings were configurable instead of needing to create a copy of an existing picker.

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

I changed my mapping for live grep to use a custom attach_mapping:

local refine_word_action = function(prompt_bufnr)
  require("telescope.actions.generate").refine(prompt_bufnr, {
    prompt_title = "Refine word results",
  })
end

local attach_mappings = function(_, map)
  map("i", "<c-space>", refine_word_action)
  return true
end

vim.keymap.set("<leader>sg", function() require("telescope.builtin").live_grep({ attach_mappings = attach_mappings }) end)

To check:

1. Execute the mapping, e.g. <leader>sg
2. search some text to populate the search buffer (e.g. telescope)
3. press the refinement shortcut (e.g. <c-space>)

The prompt title should now read "Refine word results"

Configuration:

• Neovim version (nvim --version): NVIM v0.10.3
• Operating system and version: macOS Sequonia Version 15.1.1

Checklist:

• My code follows the style guidelines of this project (stylua)
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (lua annotations)