fixes Wilfred#48 Problem with template parameters and "!in" and "!is"

This essentially returns the !in and !is handling to the scanner,
which is necessary to avoid confusing the parser since these are
not "words".

Author: gdamore

grammar.js

@@ -16,6 +16,8 @@ module.exports = grammar({
     $.int_literal,
     $.float_literal,
     $._string,
+    $.not_in,
+    $.not_is,
     $._after_eof,
     $.error_sentinel,
   ],
@@ -92,9 +94,6 @@ module.exports = grammar({
 
     htmlentity: ($) => token.immediate(/\\&[a-zA-Z_]+;/),
 
-    not_in: (_) => token("!in"),
-    not_is: (_) => token("!is"),
-
     end_file: (_) => token(seq(prec(100, choice(/\x1a/, /__EOF__/)))),
 
     comment: (_) =>