patch 8.1.0932: Farsi support is outdated and unused

Problem:    Farsi support is outdated and unused.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/options.txt b/runtime/doc/options.txt
index 3b62c0f..e664c96 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -688,13 +688,8 @@
 			{not in Vi}
 			{only available when compiled with the |+farsi|
 			feature}
-	When on, the second language is Farsi.  In editing mode CTRL-_ toggles
-	the keyboard map between Farsi and English, when 'allowrevins' set.
-
-	When off, the keyboard map toggles between Hebrew and English.  This
-	is useful to start the Vim in native mode i.e. English (left-to-right
-	mode) and have default second language Farsi or Hebrew (right-to-left
-	mode).  See |farsi.txt|.
+	This option was for using Farsi, which has been removed.  See
+	|farsi.txt|.
 
 						*'ambiwidth'* *'ambw'*
 'ambiwidth' 'ambw'	string (default: "single")
@@ -3301,9 +3296,8 @@
 			{not in Vi}
 			{only available when compiled with the |+rightleft|
 			feature}
-	When on, the keyboard is mapped for the Farsi character set.
-	Normally you would set 'allowrevins' and use CTRL-_ in insert mode to
-	toggle this option |i_CTRL-_|.  See |farsi.txt|.
+	This option was for using Farsi, which has been removed.  See
+	|farsi.txt|.
 
 						*'foldclose'* *'fcl'*
 'foldclose' 'fcl'	string (default "")