Adding upstream version 2:9.1.1230.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

runtime/compiler/vimdoc.vim

@@ -0,0 +1,20 @@
+" Vim Compiler File
+" Language:             vimdoc
+" Maintainer:           Wu, Zhenyu <wuzhenyu@ustc.edu>
+" Latest Revision:      2024-04-13
+"
+" If you can not find 'vimdoc' in the package manager of your distribution e.g
+" 'pip', then you may need to build it from its source.
+
+if exists('b:current_compiler')
+  finish
+endif
+let b:current_compiler = 'vimdoc'
+
+let s:save_cpoptions = &cpoptions
+set cpoptions&vim
+
+CompilerSet makeprg=vimdoc
+
+let &cpoptions = s:save_cpoptions
+unlet s:save_cpoptions