Update runtime files

runtime/indent/rrst.vim

@@ -2,7 +2,7 @@
 " Language:	Rrst
 " Author:	Jakson Alves de Aquino <jalvesaq@gmail.com>
 " Homepage:     https://github.com/jalvesaq/R-Vim-runtime
-" Last Change:	Tue Apr 07, 2015  04:38PM
+" Last Change:	Feb 25, 2023
 
 
 " Only load this indent file when no other was loaded.
@@ -16,6 +16,8 @@ let b:did_indent = 1
 setlocal indentkeys=0{,0},:,!^F,o,O,e
 setlocal indentexpr=GetRrstIndent()
 
+let b:undo_indent = "setl inde< indk<"
+
 if exists("*GetRrstIndent")
   finish
 endif