chore: add type annotations to (almost) all functions

lua/nvim-tree/explorer/explore.lua

@@ -11,10 +11,17 @@ local Watcher = require "nvim-tree.watcher"
 
 local M = {}
 
+---@param type_ string|nil
+---@param cwd string
+---@return any
 local function get_type_from(type_, cwd)
   return type_ or (vim.loop.fs_stat(cwd) or {}).type
 end
 
+---@param handle uv_fs_t
+---@param cwd string
+---@param node Node
+---@param git_status table
 local function populate_children(handle, cwd, node, git_status)
   local node_ignored = explorer_node.is_git_ignored(node)
   local nodes_by_path = utils.bool_record(node.nodes, "absolute_path")
@@ -53,6 +60,9 @@ local function populate_children(handle, cwd, node, git_status)
   end
 end
 
+---@param node Node
+---@param status table
+---@return Node[]|nil
 function M.explore(node, status)
   local cwd = node.link_to or node.absolute_path
   local handle = vim.loop.fs_scandir(cwd)