add preprocessor highlighting to pism syntax file

scripts/pism.vim

@@ -4,14 +4,18 @@ endif
 
 syn keyword sapviKeyword constant contract start end
 "syn keyword sapviAttr
-syn keyword sapviType FixedGenerator BlakePersonalization PedersenPersonalization ByteSize U64 Fr Point Bool Scalar
+syn keyword sapviType FixedGenerator BlakePersonalization PedersenPersonalization ByteSize U64 Fr Point Bool Scalar BinarySize
 syn match sapviFunction "^[ ]*[a-z_0-9]* "
 syn match sapviComment "#.*$"
 syn match sapviNumber ' \zs\d\+\ze'
 syn match sapviConst '[A-Z_]\{2,}[A-Z0-9_]*'
+syn match sapviPreproc "{%.*%}"
+syn match sapviPreproc2 "{{.*}}"
 
 hi def link sapviKeyword    Statement
 "hi def link sapviAttr       StorageClass
+hi def link sapviPreproc    PreProc
+hi def link sapviPreproc2   PreProc
 hi def link sapviType       Type
 hi def link sapviFunction   Function
 hi def link sapviComment    Comment