patch 8.1.0932: Farsi support is outdated and unused

Problem:    Farsi support is outdated and unused.
Solution:   Delete the Farsi support.
diff --git a/runtime/doc/starting.txt b/runtime/doc/starting.txt
index 6289e9c..9f64726 100644
--- a/runtime/doc/starting.txt
+++ b/runtime/doc/starting.txt
@@ -321,9 +321,8 @@
 		and exits.)  {not in Vi}
 
 							*-F*
--F		Farsi mode.  Sets the 'fkmap' and 'rightleft' options on.
-		(Only when compiled with |+rightleft| and |+farsi| features,
-		otherwise Vim gives an error message and exits.)  {not in Vi}
+-F		This was used for Farsi mode, which has been removed.
+		See |farsi.txt|.
 
 							*-H*
 -H		Hebrew mode.  Sets the 'hkmap' and 'rightleft' options on.