fix: set variable if it's a first install

lua/config/lazy.lua

@@ -1,8 +1,8 @@
 local lazypath = vim.fn.stdpath "data" .. "/lazy/lazy.nvim"
 if not vim.loop.fs_stat(lazypath) then
+  vim.g.astronvim_first_install = true
   -- stylua: ignore
-  vim.fn.system({ "git", "clone", "--filter=blob:none", "https://github.com/folke/lazy.nvim.git", "--branch=stable",
-    lazypath })
+  vim.fn.system({ "git", "clone", "--filter=blob:none", "https://github.com/folke/lazy.nvim.git", "--branch=stable", lazypath })
 end
 vim.opt.rtp:prepend(vim.env.LAZY or lazypath)