Update grammar.ebnf

grammar.ebnf

-/* Amount: quantity of an ingredient, exclusively */
-/* does not refer to time, size etc */
+Ambiguator ::= ("<" | ">" | "less than" | "more than")
+
+/* Amount: quantity of an ingredient */
 /* Eg: 10 - 20 g of pasta */
-Amount ::= Digit+ ("-" | "/" | "to")? Digit*
+Amount ::= Ambiguator* Digit+ ("-" | "/" | "to")? Digit*
 
 /* Digit: */
 Digit ::= ("0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9")+
@@ -12,7 +13,7 @@ Digit ::= ("0" | "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9")+
 Unit ::=
 
 /* Ingredient: */
-Ingredient ::= Modification* ","* Ingredient
+Ingredient ::= Modifier* Ingredient (Modifier ",")*
 
 /* Modifier: a word or phrase that modifies the ingredient */
 /* Eg: "pears, chopped", "chopped pears", "chicken, skin on" */