runtime(cabal): include cabal ftplugin file

closes: #15158

Signed-off-by: Riley Bruins <ribru17@hotmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/ftplugin/cabal.vim b/runtime/ftplugin/cabal.vim
new file mode 100644
index 0000000..5ccfa1d
--- /dev/null
+++ b/runtime/ftplugin/cabal.vim
@@ -0,0 +1,13 @@
+" Vim filetype plugin file
+" Language:	Haskell Cabal Build file
+" Maintainer:	Riley Bruins <ribru17@gmail.com>
+" Last Change:	2024 Jul 06
+
+if exists('b:did_ftplugin')
+  finish
+endif
+let b:did_ftplugin = 1
+
+setl comments=:-- commentstring=--\ %s
+
+let b:undo_ftplugin = 'setl com< cms<'