Code block syntax in markdown does not render in html

In the tutorial, we can typeset code in markdown as such:

```{.python .input}
1+2+3
```

however, I'd like the original RTD syntax with additional code blocks such as `linenos`, which helps to point out the line number.

```
.. code-block:: python
    :linenos:

    a = 2
    b = 3
```

Are there any hacks to make this appear?