#### 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
.then(handleUserResponse)
	.catch(handleError);
axios.post<User>('/user', { foo: 'bar' })
	.then(handleUserResponse)
	.catch(handleError);
axios.post<User>('/user', { foo: 'bar' }, { headers: { 'X-FOO': 'bar' } })
	.then(handleUserResponse)
	.catch(handleError);
axios.put<User>('/user', { foo: 'bar' })
	.then(handleUserResponse)
	.catch(handleError);
axios.patch<User>('/user', { foo: 'bar' })
	.then(handleUserResponse)
  .catch(handleError);
const handleStringResponse = (response: string) => {
  console.log(response)
}
axios.get<User, string>('/user?id=12345')
  .then(handleStringResponse)
  .catch(handleError);
axios.get<User, string>('/user', { params: { id: 12345 } })
  .then(handleStringResponse)
  .catch(handleError);
axios.head<User, string>('/user')
  .then(handleStringResponse)
  .catch(handleError);
axios.options<User, string>('/user')
  .then(handleStringResponse)
  .catch(handleError);
axios.delete<User, string>('/user')