Add definition of my_integer_sequence.

README.md

@@ -100,6 +100,11 @@ MyContainer c2; // OK MyContainer<float>
 ### Declaring non-type template parameters with auto
 Following the deduction rules of `auto`, while respecting the non-type template parameter list of allowable types[\*], template arguments can be deduced from the types of its arguments:
 ```c++
+template <auto ... seq>
+struct my_integer_sequence {
+  // Implementation here ...
+};
+
 // Explicitly pass type `int` as template argument.
 auto seq = std::integer_sequence<int, 0, 1, 2>();
 // Type is deduced to be `int`.