Make note file extensions configurable in VSCode Notebook

Components

My suggestion is for the notes in VSCodeNotebook. Right now, only txt and md format are considered as notes. We should have more formats that should be considered as "notes".

Proposal

To enable this feature, we can have a setting in settings.json. That setting should be an array which accepts the list of extensions that VSCodeNotebook can accept. It will look probably like this.

{
    "note_extensions": [
        "txt",
        "md"
    ],
]

Mockups / Examples

Once implemented, users will be able to write notes in any format they prefer. To do so, they will simply have to add the corresponding extension in JSON file.

For example, if they want to add rst support and remove md support, they will change the setting like this -

{
    "note_extensions": [
        "txt",
        "rst"
    ],
}

Benefits

Once this feature is implemented, the software will become more customizable and thus more usuable to a diverse set of users. For example, they will be able to encrypt notes written in rst format. Some users have requested this feature and this will fix their problem.

I have opened an issue for the same on GitHub (aviaryan is my GitHub username) - aviaryan/VSCodeNotebook#7