Missing type information in `mojo doc` JSON for parametric aliases (new feature in nightly)

Given this example parametric alias:

alias ParametricAlias[x: Int]: Int = x + 1

It is currently not possible to reconstruct the signature from the mojo doc JSON.

Actual behavior

In the JSON, the alias looks like this:

{
    "deprecated": "",
    "description": "",
    "kind": "alias",
    "name": "ParametricAlias",
    "parameters": [
        {
            "description": "",
            "kind": "parameter",
            "name": "x",
            "passingKind": "pos_or_kw",
            "type": "Int"
        }
    ],
    "summary": "A parametric alias",
    "value": "(x + 1)"
}

While the type of the parameter is provided, the type of the alias itself is missing.

Expected behavior

Provide the type of the alias in the mojo doc JSON.
Alternatively, provide the full alias signature as a field of the JSON.

Filed a bug report: #4980