Refactor: switch from packer to lazy.vim

- Packer is no longer maintained (as of August, 2023)

.config/nvim/init.lua

@@ -1 +1,8 @@
+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", "https://github.com/folke/lazy.nvim.git", "--branch=stable",
+                   lazypath})
+end
+vim.opt.rtp:prepend(lazypath)
+
 require("cole")