nvim: Migrate configuration to lua and built-in plugin manager

nvim/lua/plugins/neotree.lua

@@ -0,0 +1,16 @@
+vim.pack.add({
+    {
+        src = gh("nvim-neo-tree/neo-tree.nvim"),
+        version = vim.version.range("3")
+    },
+    gh("nvim-lua/plenary.nvim"),
+    gh("MunifTanjim/nui.nvim"),
+    gh("nvim-tree/nvim-web-devicons"),
+})
+
+require("neo-tree").setup({
+    window = {
+        position = "left",
+        width = 50,
+    },
+})