patch 9.1.0811: :find expansion does not consider 'findexpr'

Problem:  :find expansion does not consider 'findexpr'
Solution: Support expanding :find command argument using 'findexpr'
          (Yegappan Lakshmanan)

closes: #15929

Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 5593523..229ce13 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -3552,7 +3552,7 @@
 	  eob		EndOfBuffer		|hl-EndOfBuffer|
 	  lastline	NonText			|hl-NonText|
 
-						*'findexpr'* *'fexpr'*
+						*'findexpr'* *'fexpr'* *E1514*
 'findexpr' 'fexpr'	string	(default "")
 			global or local to buffer |global-local|
 			{not available when compiled without the |+eval|