Update rule hash implementation

src/compiler/rules/string.h

@@ -8,7 +8,9 @@ namespace tree_sitter  {
         class String : public Rule {
         public:
             String(std::string value);
+
             bool operator==(const Rule& other) const;
+            size_t hash_code() const;
             std::string to_string() const;
             void accept(Visitor &visitor) const;