Add syntax files from upstream vim repository

ftplugin/sbt.vim

@@ -0,0 +1,19 @@
+if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'vim') == -1
+  
+" Vim filetype plugin file
+" Language:     sbt
+" Maintainer:   Steven Dobay <stevendobay at protonmail.com>
+" License:      Same as Vim
+" Last Change:  2017.04.30
+" ----------------------------------------------------------------------------
+
+if exists('b:did_ftplugin') || &cp
+  finish
+endif
+
+let b:did_ftplugin = 1
+
+runtime! ftplugin/scala.vim
+
+
+endif