Enhance ZON parser to support tuples and update documentation

- Modify parser to handle ZON tuples (`.{ 1, 2, 3 }`) as arrays
- Update README with more detailed explanation of ZON tuple syntax
- Add multiple example ZON files demonstrating tuple usage
- Implement tuple parsing in `parser.py`
- Add test case for tuple parsing

examples/tuple_test.zon

@@ -0,0 +1,6 @@
+.{
+    .simple_tuple = .{ 1, 2, 3 },
+    .string_tuple = .{ "one", "two", "three" },
+    .empty_tuple = .{""},
+    .mixed_tuple = .{ 1, "two", true },
+}