Migrate from JSHint to ESLint for linting in CodeMirror

Nature of issue?

p5 Web Editor doesn't support Private Class Fields

• Enhancement

(Private Class Fields is probably a new thing)

Note that Private Class fields is "an experimental proposal to allow defining private class fields using a hash prefix", hence this is not considered a bug.

Details:

Private class properties, or "Hash" names, as stated in the MDN Docs; are not supported by the Web Editor.

Though the code works, the editor comes with an error.

• Steps to reproduce:

class ClassWithPrivateField {
  #privateField
  constructor() {
    this.#privateField = 42;
    this.something = 23;
  }
}

MDN Web Docs on Private Class Fields

Start by reconciling the title's JSHint-to-ESLint migration with the body’s private class fields report, then reproduce the supplied JavaScript snippet in the p5 Web Editor. Trace the editor’s linting or parsing configuration, and consider the work done when the snippet no longer produces an editor error and the intended linting setup is covered by tests.