vim.ui.input buffer that auto-resizes to fit its contents.
feat: add M.setup function for global configuration
introduce M.setup to provide a global entrypoint for configuring
vim.ui.input with default options. this refactors the vim.ui.input
override from plugin/wrapinput.lua into the main module. also rename
lua/wrapinput/init.lua to lua/wrapinput.lua for consistency