add vim syntax highlighter

vim/ftdetect/x20.vim

@@ -0,0 +1 @@
+au BufRead,BufNewFile *.x20 setfiletype x20

vim/ftplugin/x20.vim

@@ -0,0 +1,8 @@
+if exists("b:did_ftplugin")
+  finish
+endif
+
+setlocal commentstring={%s}
+setlocal matchpairs={:},::;,!:;
+
+let b:did_ftplugin = 1

vim/syntax/x20.vim

@@ -0,0 +1,15 @@
+syn match x20com "{.*}"
+syn match x20fun "-\S*"
+syn match x20num "#\S*\|@\S*"
+syn match x20pun ":\S*\|!\S*\|;"
+
+syn region x20str matchgroup=x20str start=/"/ end=/"/
+syn sync fromstart
+
+hi link x20com comment
+hi link x20fun type
+hi link x20num number
+hi link x20pun delimiter
+hi link x20str string
+
+let b:current_syntax='x20'