#### Summary

It would be nice to export a typeguard from Axios' index.d.ts.
This way, consumers trying to do error handling can check in a type-safe way if the error is an AxiosError, or some other kind of error.

It's easy enough to do this as a consumer, but it would be nicer if this was included in the actual Axios library.

test/typescript/axios.ts
} else {
    console.log(error.message);
  }
};
axios(config)
  .then(handleResponse)
  .catch(handleError);
axios.get('/user?id=12345')
  .then(handleResponse)
  .catch(handleError);
axios.get('/user', { params: { id: 12345 } })
  .then(handleResponse)
  .catch(handleError);
axios.head('/user')
  .then(handleResponse)
  .catch(handleError);
axios.options('/user')
  .then(handleResponse)
  .catch(handleError);
axios.delete('/user')
  .then(handleResponse)
  .catch(handleError);
axios.post('/user', { foo: 'bar' })
  .then(handleResponse)
  .catch(handleError);
axios.post('/user', { foo: 'bar' }, { headers: { 'X-FOO': 'bar' } })
  .then(handleResponse)
  .catch(handleError);
axios.put('/user', { foo: 'bar' })
  .then(handleResponse)