patch 8.1.1614: 'numberwidth' can only go up to 10

Problem:    'numberwidth' can only go up to 10.
Solution:   Allow up to 20. (Charlie Stanton, closes #4584)
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 6bbe428..e6c9992 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -1,4 +1,4 @@
-*options.txt*	For Vim version 8.1.  Last change: 2019 Jun 22
+*options.txt*	For Vim version 8.1.  Last change: 2019 Jun 27
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -5385,7 +5385,7 @@
 	rows in the window, depending on whether 'number' or 'relativenumber'
 	is set. Thus with the Vim default of 4 there is room for a line number
 	up to 999. When the buffer has 1000 lines five columns will be used.
-	The minimum value is 1, the maximum value is 10.
+	The minimum value is 1, the maximum value is 20.
 	NOTE: This option is set to the Vi default value when 'compatible' is
 	set and to the Vim default value when 'compatible' is reset.
 
@@ -8070,7 +8070,7 @@
 	already.
 	Additionally, if vim is compiled with the |+termresponse| feature and
 	|t_RV| is set to the escape sequence to request the xterm version
-	number, more intelligent detection process runs.
+	number, more intelligent detection is done.
 	The "xterm2" value will be set if the xterm version is reported to be
 	from 95 to 276.  The "sgr" value will be set if Vim detects Mac
 	Terminal.app, iTerm2 or mintty, and when the xterm version is 277 or