patch 8.0.1845: various comment updates needed, missing white space

Problem:    Various comment updates needed, missing white space.
Solution:   Update comments, add white space.
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 921765c..b05a479 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -1,4 +1,4 @@
-*options.txt*	For Vim version 8.0.  Last change: 2018 Apr 22
+*options.txt*	For Vim version 8.0.  Last change: 2018 May 15
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -2561,8 +2561,11 @@
 	contain a list of words.  This can be one word per line, or several
 	words per line, separated by non-keyword characters (white space is
 	preferred).  Maximum line length is 510 bytes.
-	When this option is empty, or an entry "spell" is present, spell
-	checking is enabled the currently active spelling is used. |spell|
+
+	When this option is empty or an entry "spell" is present, and spell
+	checking is enabled, words in the word lists for the currently active
+	'spelllang' are used. See |spell|.
+
 	To include a comma in a file name precede it with a backslash.  Spaces
 	after a comma are ignored, otherwise spaces are included in the file
 	name.  See |option-backslash| about using backslashes.