Vscode_deno: deno.ignore setting

[Vehmloewff]

Is your feature request related to a problem? Please describe.

Often I need to embed bits of a Nodejs project in my Deno project.

When deno.enable is true the Nodejs typescript files display all sorts of errors due to the differences between conventional typescript and Deno typescript.

Describe the solution you'd like

The best solution I can think of right now would be to add a deno.ignore setting to this extension.

```json
// .vscode/settings.json
{
"deno.enable": true,
"deno.ignore": [ "src/embeded-node-project/*/" ]
}

[MarkTiedemann]

Another option would be to allow enabling Deno only for a specific set of files:

{
    "deno.enable": [
        "src/deno/*"
    ]
}