patch 9.1.0000: Vim 9.1 release

Problem:  Need a new release
Solution: Release Vim 9.1

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/README.txt b/README.txt
index 159e8ae..5128afd 100644
--- a/README.txt
+++ b/README.txt
@@ -1,4 +1,4 @@
-README.txt for version 9.0 of Vim: Vi IMproved.
+README.txt for version 9.1 of Vim: Vi IMproved.
 
 
 WHAT IS VIM?