added oil toggle_float keymap

lua/keymaps.lua

@@ -27,6 +27,7 @@ mapleader("s",  vim.cmd.source)
 mapleader("w",  vim.cmd.write)
 mapleader("f",  vim.lsp.buf.format)
 mapleader("o",  function() oil.open() end)
+mapleader("O",  function() oil.toggle_float() end)
 mapleader("pf", function() pick.builtin.files() end)
 mapleader("pg", function() pick.builtin.grep_live() end)
 mapleader("ph", function() pick.builtin.help() end)