Updated runtime files.

Add Serbian translations and spell checking.
diff --git a/runtime/doc/usr_05.txt b/runtime/doc/usr_05.txt
index 67b33bd..ee40463 100644
--- a/runtime/doc/usr_05.txt
+++ b/runtime/doc/usr_05.txt
@@ -1,4 +1,4 @@
-*usr_05.txt*	For Vim version 8.0.  Last change: 2016 Mar 28
+*usr_05.txt*	For Vim version 8.0.  Last change: 2018 Feb 20
 
 		     VIM USER MANUAL - by Bram Moolenaar
 
@@ -48,6 +48,14 @@
 	$HOME/_vimrc ~
 	$VIM/_vimrc ~
 
+If you are creating the vimrc file for the first time, it is recommended to
+put this line at the top: >
+
+	source $VIMRUNTIME/defaults.vim
+
+This initializes Vim for new users (as opposed to traditional Vi users). See
+|defaults.vim| for the details.
+
 The vimrc file can contain all the commands that you type after a colon.  The
 most simple ones are for setting options.  For example, if you want Vim to
 always start with the 'incsearch' option on, add this line your vimrc file: >