Change address.countryCode method signature

[xDivisionByZerox]

The Problem

Existing comment about this issue:
By @ST-DDT: Limit the parameter to the two values.

faker/src/address.ts

Lines 289 to 306 in f476859

	// TODO ST-DDT 2022-02-10: Limit the parameter to the two values.
	countryCode(alphaCode: string = 'alpha-2'): string {
	if (alphaCode === 'alpha-2') {
	return this.faker.random.arrayElement(
	this.faker.definitions.address.country_code
	);
	}
	if (alphaCode === 'alpha-3') {
	return this.faker.random.arrayElement(
	this.faker.definitions.address.country_code_alpha_3
	);
	}
	return this.faker.random.arrayElement(
	this.faker.definitions.address.country_code
	);
	}

The Solution

Only except 'alpha-2' and 'alpha-3' as valid string inputs

countryCode(alphaCode: 'alpha-2' | 'alpha-3' = 'alpha-2'): string

[ST-DDT]

Not sure, whether this should be in v6.1 or v6.2,

[xDivisionByZerox]

We could first put this in v6.2. But can put in v6.1 if we magically get everything else done?^^

[xDivisionByZerox]

I provided a PR that fixes this. Please assign me to this issue.