vim.bo.tabstop = 4 -- size of a hard tabstop (ts).
vim.bo.shiftwidth = 4 -- size of an indentation (sw).
vim.bo.expandtab = true -- always uses spaces instead of tab characters (et).
vim.bo.softtabstop = 4 -- number of spaces a <Tab> counts for. When 0, feature is off (sts).