Update runtime files

runtime/ftplugin/vdf.vim

@@ -0,0 +1,14 @@
+" Vim filetype plugin
+" Language:	Valve Data Format
+" Maintainer:	ObserverOfTime <chronobserver@disroot.org>
+" Last Change:	2022 Sep 15
+
+if exists('b:did_ftplugin')
+  finish
+endif
+let b:did_ftplugin = 1
+
+setl comments=:// commentstring=//\ %s
+setl foldmethod=syntax
+
+let b:undo_ftplugin = 'setl com< cms< fdm<'