vim: make lualine config clearer with some comments

nvim/.config/nvim/after/plugin/lualine.lua

@@ -28,7 +28,12 @@ local paste = {
   color = { fg = colors.base3, bg = colors.yellow, gui = 'bold' },
   cond = function() return vim.opt.paste:get() end
 }
-local relative_path = { 'filename', path = 1 }
+
+local relative_path = {
+  'filename',
+  path = 1  -- 0: just filenane, 1: realtive path, 2: absolute path
+}
+
 local encoding = function ()
   local fenc = vim.opt.fileencoding:get()
   if fenc ~= '' then
@@ -36,7 +41,10 @@ local encoding = function ()
   end
   return vim.opt.encoding:get()
 end
+
+-- let padding when using icons leaves too much space
 local fileformat = { 'fileformat', padding = { left = 0, right = 1} }
+
 local progress = '%3l/%L｜%-2v'  -- line / total ｜column
 
 require('lualine').setup {