Note that @index has sugar in README

Author: mkantor

README.md

@@ -155,7 +155,8 @@ desugars to `{@lookup key: foo}`. All such expressions have a key `0` referring
 to a value that is an `@`-prefixed atom (the keyword). Keywords include
 `@function`, `@lookup`, `@apply`, `@check`, `@index`, and `@runtime`.
 
-Currently only `@function`, `@lookup`, and `@apply` have syntax sugars.
+Currently only `@function`, `@lookup`, `@index`, and `@apply` have syntax
+sugars.
 
 ### Semantics