Configuration settings for html/css validation

[justinribeiro]

@sjmiles noted this in mjbvz/vscode-lit-html#42

I tried to solve this by disabling validation, i.e.

"html.validate.styles": false,
"css.validate": false
which had no effect.

Ideally ts-lit-html-plugin honors those configuration options.

With the update to StyledTemplateLanguageService, I'm wondering what your thoughts are on updating the TsHtmlPluginConfiguration interface to be enable validate and lint configuration options similar to styled? Or if there's a better configuration integration approach I'm not quite seeing.

[mjbvz]

Yes we should at least expose a way to disable validation. I propose a setting like:

{
  "compilerOptions": {
    "plugins": [
      {
        "name": "typescript-lit-html-plugin",
        "css": { "validate": false }
      }
    ]
  }
}

The styled plugin has a number of settings that are also supported: https://github.com/Microsoft/typescript-styled-plugin#configuration