docs: Extend TypeScript example

[justsml]

After using my original example (#440) a bit more in production, I've found it super handy to be able to pass in config overrides per test file.

Description

Now you can invoke the helper like so:

Example: Ignoring headers (API Keys)

const polly = autoSetupPolly({
  matchRequestsBy: {
    headers: { exclude: ['x-request-id', 'x-api-key'] },
  }
});

Example: Ignoring generated data using a callback

const polly = autoSetupPolly({
 matchRequestsBy: {
   body(body, req) {
     const json = JSON.parse(body);

     delete json.uuid;
     delete json.createdDate;

     return JSON.stringify(json);
   }
});

Motivation and Context

Sharing my improved code back upstream ❤️

Types of Changes

• [x] New feature (non-breaking change which adds functionality)

Checklist

• [x] I have added tests to cover my changes.
• [x] My change requires a change to the documentation.
• [x] I have updated the documentation accordingly.
• [x] My code follows the code style of this project.
• [x] My commits and the title of this PR follow the Conventional Commits Specification.
• [x] I have read the contributing guidelines.