contrib: Add Vim highlighting for zkas.

contrib/zk.vim

@@ -0,0 +1,38 @@
+" Syntax highlighting for zkas scripts.
+" Symlink into ~/.vim/syntax/zk.vim
+
+if exists("b:current_syntax")
+    finish
+endif
+
+syn keyword zkasKeyword 
+    \ constant
+    \ contract
+    \ circuit
+
+syn keyword zkasType 
+    \ EcPoint EcFixedPoint EcFixedPointBase EcFixedPointShort
+    \ Base BaseArray Scalar ScalarArray
+    \ MerklePath
+    \ Uint32 Uint64
+
+syn keyword zkasInstruction
+    \ ec_add ec_mul ec_mul_base ec_mul_short
+    \ ec_get_x ec_get_y
+    \ base_add base_mul base_sub
+    \ poseidon_hash calculate_merkle_root
+    \ constrain_instance
+
+syn region zkasString start='"' end='"' contained
+
+syn keyword zkasTodo contained TODO FIXME XXX NOTE
+syn match zkasComment "#.*$" contains=zkasTodo
+
+hi def link zkasKeyword      Statement
+hi def link zkasType         Type
+hi def link zkasInstruction  Function
+hi def link zkasString       Constant
+hi def link zkasTodo         Todo
+hi def link zkasComment      Comment
+
+let b:current_syntax = "zk"