Flag for "vi" is wrong

[MuTsunTsai]

Describe the bug
This is similar to issue #489, and this time the flag for locale "vi" is displayed as that of U.S. Virgin Islands but it should have been the flag of Vietnam instead (it will correctly show Vietnam if the "vi-VN" is specified though).

Extension Version
i18n Ally v2.5.3

Screenshots

[antfu]

We have these flags:

https://github.com/lokalise/i18n-ally/blob/master/res/flags/vn.svg
https://github.com/lokalise/i18n-ally/blob/master/res/flags/vi.svg

It might be confused with the county code and locale code, what's your suggestion here?

Maybe we should add an entry to this with 'vi': 'vn'?

i18n-ally/src/meta.ts

Lines 25 to 32 in ff6f406

	export const DEFAULT_LOCALE_COUNTRY_MAP = {
	en: 'us',
	zh: 'cn',
	de: 'de',
	fr: 'fr',
	ja: 'ja',
	es: 'es',
	}

[MuTsunTsai]

Yes, I would say that's the way to go. And you guys might also want to generalize it to more locale codes as well.