feat(neovim): add GitHub Copilot and CopilotChat plugins

This commit introduces two new plugins to the Neovim configuration:
GitHub Copilot and CopilotChat. The GitHub Copilot plugin is added
directly, while the CopilotChat plugin is added with a custom setup
function. The setup function configures key mappings and prompts for
the CopilotChat plugin. Additionally, a new global variable
`install_copilot` is introduced to control the installation of these
plugins.

neovim/lua/plugins.lua

@@ -619,6 +619,20 @@ use({
     disable = not vim.g.install_sourcegraph,
 })
 
+use({
+    "https://github.com/github/copilot.vim",
+    disable = not vim.g.install_copilot,
+})
+
+use({
+    "https://github.com/CopilotC-Nvim/CopilotChat.nvim",
+    disable = not vim.g.install_copilot,
+    branch = "canary",
+    config = function()
+        require("plugins.copilotchat").setup()
+    end,
+})
+
 -- Auto sync after bootstrapping on a fresh box
 if packer_bootstrap ~= "" then
     packer.sync()

neovim/lua/plugins/copilotchat.lua

@@ -0,0 +1,40 @@
+local M = {}
+
+function M.setup()
+    require("CopilotChat").setup({
+        mappings = {
+            complete = {
+                insert = "",
+            },
+        },
+        prompts = {
+            Explain = {
+                prompt = "/COPILOT_EXPLAIN Write a concise explanation for the active selection as paragraphs of text.",
+            },
+        },
+    })
+
+    local utils = require("utils")
+    if utils.try_require("telescope") ~= nil then
+        local cc_keymap = utils.curry_keymap("n", "<leader>cc")
+
+        cc_keymap("h", function()
+            local actions = require("CopilotChat.actions")
+            require("CopilotChat.integrations.telescope").pick(actions.help_actions())
+        end, { desc = "CopilotChat - Help" })
+
+        cc_keymap("p", function()
+            local actions = require("CopilotChat.actions")
+            require("CopilotChat.integrations.telescope").pick(actions.prompt_actions())
+        end, { desc = "CopilotChat - Prompt" })
+
+        cc_keymap("c", function()
+            local input = vim.fn.input("Quick Chat: ")
+            if input ~= nil and input ~= "" then
+                require("CopilotChat").ask(input, { selection = require("CopilotChat.select").buffer })
+            end
+        end, { desc = "CopilotChat - Quick Chat" })
+    end
+end
+
+return M

neovim/lua/variables.lua

@@ -1 +1,2 @@
+vim.g.install_copilot = false
 vim.g.install_sourcegraph = false