add type annotations and format

lua/custom/keymap.lua

 local M = {}
 
+---@param keys string
+---@param func string|function
+---@param desc string
+---@param bufnr integer
 function M.nmap(keys, func, desc, bufnr)
   vim.keymap.set('n', keys, func, { buffer = bufnr, silent = true, noremap = true, desc = desc })
 end

lua/custom/list.lua

 local M = {}
 
--- return true if the `value` is inside the `list`, false otherwise
-function M.is_in(value, list)
-  for _, item in ipairs(list) do
-    if value == item then
+-- return `true` if the `v` is inside the `values`, `false` otherwise
+--
+---@generic T: any
+---@param v T
+---@param values T[]
+---@return boolean
+function M.is_in(v, values)
+  for _, item in ipairs(values) do
+    if v == item then
       return true
     end
   end

lua/custom/plugins/aerial.lua

@@ -9,7 +9,7 @@ return {
     config = function()
       local aerial = require("aerial")
       aerial.setup({
-        on_attach = function(bufnr)
+        on_attach = function(bufnr --[[@param bufnr integer]])
           vim.keymap.set('n', '<leader>ap', aerial.prev, { buffer = bufnr })
           vim.keymap.set('n', '<leader>an', aerial.next, { buffer = bufnr })
         end

lua/custom/plugins/git.lua

@@ -14,7 +14,7 @@ return {
         topdelete = { text = '‾' },
         changedelete = { text = '~' },
       },
-      on_attach = function(bufnr)
+      on_attach = function(bufnr --[[@param bufnr integer]])
         local gs = require("gitsigns")
 
         local function map(mode, lhs, rhs, opts)

lua/custom/telescope.lua

@@ -26,7 +26,7 @@ M.multigrep = function(opts)
   opts.cwd = opts.cwd or vim.uv.cwd()
 
   local finder = finders.new_async_job {
-    command_generator = function(prompt)
+    command_generator = function(prompt --[[@param prompt string]])
       if not prompt or prompt == "" then
         return nil
       end

plugin/lol.lua

@@ -17,8 +17,8 @@ local non_default_entries = { url_entry, unpack(lsp_entries) }
 
 local popup_menu_group = vim.api.nvim_create_augroup("nvim_popupmenu", { clear = true })
 
-local disable = function(x) vim.cmd("amenu disable " .. x) end
-local enable = function(x) vim.cmd("amenu enable " .. x) end
+local disable = function(x --[[ @param x string]]) vim.cmd("amenu disable " .. x) end
+local enable = function(x --[[ @param x string]]) vim.cmd("amenu enable " .. x) end
 
 vim.api.nvim_create_autocmd("MenuPopup", {
   pattern = "*",

plugin/terminal.lua

@@ -5,6 +5,12 @@ local state = {
   }
 }
 
+---@class Size
+---@field height integer
+---@field width integer
+
+---@param pos string
+---@param size Size
 local open_terminal = function(pos, size)
   return function()
     vim.cmd.new()