Simplify the example code

tips.md

@@ -25,23 +25,18 @@ Resort to this only if git cannot get updated certificates or if Github has TLS/
 You can even go a step further and make `:PlugInstall` run on startup if there are any missing plugins.
 
 ```vim
+" Put this code before Plug block (plug#begin ~ plug#end)
+
 " Install vim-plug if not found
 if empty(glob('~/.vim/autoload/plug.vim'))
   silent !curl -fLo ~/.vim/autoload/plug.vim --create-dirs
     \ https://raw.githubusercontent.com/junegunn/vim-plug/master/plug.vim
 endif
 
-call plug#begin()
-if exists('g:loaded_plug')
-  " Uncommment the following line to install documentation
-  " Plug 'junegunn/vim-plug'
-  call plug#end()
-endif
-
 " Run PlugInstall if there are missing plugins
-if exists('g:plugs') && len(filter(values(g:plugs), '!isdirectory(v:val.dir)'))
-  autocmd VimEnter * PlugInstall --sync | source $MYVIMRC
-endif
+autocmd VimEnter * if len(filter(values(g:plugs), '!isdirectory(v:val.dir)'))
+  \| PlugInstall --sync | source $MYVIMRC
+\| endif
 ```
 
 Note that this may increase the startup time of Vim.