Allow custom dictionaries for jupyter notebook

[colinfang]

The screenshot shows the spell check from .ipynb & .py

It seems .ipynb ignores some default libraries loaded for python file. Hence it complains about .arange & dtype in .ipynb but not .py

Also, I tried to add custom dictionary myDict via

    "languageSettings": [
        {
            "languageId": "python",
            "dictionaries": [
                "wordsEn",
                "python",
                "data-science",
                "myDict"
            ]
        }
    ],

The setting works for .py, but not .ipynb

Have I missed anything?