Add support for local overrides in lua/local.lua

GUI's like Neovide require system specific settings for font size based
on monitor resolution, pixel density, and scaling. Add support for
loading `lua/local.lua` if it exists to enable overriding the default
for `vim.o.guifont` or similar options.

init.lua

@@ -6,6 +6,9 @@ if vim.g.neovide then
   vim.g.neovide_cursor_animation_length = 0
 end
 
+-- load config from lua/local.lua if present
+pcall(function() require('local') end)
+
 local lazypath = vim.fn.stdpath('data') .. '/lazy/lazy.nvim'
 if not vim.loop.fs_stat(lazypath) then
   vim.fn.system({ 'git', 'clone', '--filter=blob:none',