Issues when using code-block and the caption option

When I use a caption for my code-blocks, I get this error:

```
(ERROR/3) Error in "code-block" directive:
unknown option: "caption"
```

Here's a test run:

```shell
$ cat test.rst
Example
=======
Just a code-block:

.. code-block:: bash
:caption: example.bash

echo "Hello, world."

$ rstcheck test.rst
Success! No issues detected.

$ restview test.rst
Listening on http://localhost:26871/
test.rst:5: (ERROR/3) Error in "code-block" directive:
unknown option: "caption".

.. code-block:: bash
:caption: example.bash

echo "Hello, world."
127.0.0.1 - - [22/Jun/2026 04:35:33] "GET / HTTP/1.1" 200 -
127.0.0.1 - - [22/Jun/2026 04:35:33] "GET /favicon.ico HTTP/1.1" 200 -
```

Start by reproducing the issue with the shown test.rst example and the restview command, then inspect how restview parses or renders the reStructuredText code-block directive. Done means the caption option is accepted without the reported error and the example remains usable in the viewer.

Written by the indexing model from the issue text.