patch 8.2.0357: cannot delete a text property matching both id and type

Problem:    Cannot delete a text property matching both id and type. (Axel
            Forsman)
Solution:   Add the "both" argument.
diff --git a/runtime/doc/textprop.txt b/runtime/doc/textprop.txt
index 6dc58b7..55a5ed3 100644
--- a/runtime/doc/textprop.txt
+++ b/runtime/doc/textprop.txt
@@ -231,6 +231,7 @@
 		{props} is a dictionary with these fields:
 		   id		remove text properties with this ID
 		   type		remove text properties with this type name
+		   both		"id" and "type" must both match
 		   bufnr	use this buffer instead of the current one
 		   all		when TRUE remove all matching text properties,
 				not just the first one