added bootstrap packer function

nvim/.config/nvim/lua/user/packer.lua

@@ -1,3 +1,16 @@
+local ensure_packer = function()
+    local fn = vim.fn
+    local install_path = fn.stdpath('data') .. '/site/pack/packer/start/packer.nvim'
+    if fn.empty(fn.glob(install_path)) > 0 then
+        fn.system({ 'git', 'clone', '--depth', '1', 'https://github.com/wbthomason/packer.nvim', install_path })
+        vim.cmd [[packadd packer.nvim]]
+        return true
+    end
+    return false
+end
+
+local packer_bootstrap = ensure_packer()
+
 return require('packer').startup(function(use)
     -- Packer can manage itself
     use 'wbthomason/packer.nvim'
@@ -53,4 +66,9 @@ return require('packer').startup(function(use)
     -- other LSP actions
     use { 'jose-elias-alvarez/null-ls.nvim' }
 
+    -- Automatically set up your configuration after cloning packer.nvim
+    if packer_bootstrap then
+        require('packer').sync()
+    end
+
 end)