Update runtime files

runtime/ftplugin/usd.vim

@@ -0,0 +1,18 @@
+" Vim filetype plugin file
+" Language:     Pixar Animation's Universal Scene Description format
+" Maintainer:   Colin Kennedy <colinvfx@gmail.com>
+" Last Change:  2023 May 9
+
+if exists("b:did_ftplugin")
+  finish
+endif
+
+let s:cpo_save = &cpo
+set cpo&vim
+
+let b:did_ftplugin = 1
+
+setlocal commentstring=#\ %s
+
+let &cpo = s:cpo_save
+unlet s:cpo_save