Repro

Hey ho 👋, this is a feature request. What do you think of allowing multiple leading or trailing underscores? There are some libraries that use double underscore (__) to avoid name clashes. Probably the most popular one is GraphQL where you can specify a __typename (see here).

Personally, I want to use camelCase or PascalCase and I'm ok with people pre- or postfixing names with underscores. We could introduce a 4th value for the leadingUnderscore and trailingUnderscore option that is called allowMultiple, like this:

{
  "rules": {
    "@typescript-eslint/naming-convention": ["warn", {
        "format": ["camelCase", "PascalCase", "UPPER_CASE"],
        "leadingUnderscore": "allowMultiple",
        "selector": "default",
        "trailingUnderscore": "allowMultiple"
    }]
  }
}