isDate(): Format 'DD.MM.YYYY' does not pass isValidFormat

[flymans]

Describe the bug

I can't set DD.MM.YYYY format, because function isValidFormat returns false.
I can't go with workaround like isDate("19.08.2021", { format: 'DD/MM/YYYY', delimiters: ["/", "."] }); because it approves dates with "/" delimeter

Examples
isDate("19/08/2021", { format: 'DD.MM.YYYY', delimiters: ["."], strictMode: true }); returns false

Additional context
Validator.js version: 13.6.1
Node.js version: 12.15.0
OS platform: [linux]

[flymans]

Is it possible to edit current function:
function isValidFormat(format) { return /(^(y{4}|y{2})[\/-](m{1,2})[\/-](d{1,2})$)|(^(m{1,2})[\/-](d{1,2})[\/-]((y{4}|y{2})$))|(^(d{1,2})[\/-](m{1,2})[\/-]((y{4}|y{2})$))/gi.test(format); }

to this:
function isValidFormat(format) { return /(^(y{4}|y{2})[.\/-](m{1,2})[.\/-](d{1,2})$)|(^(m{1,2})[.\/-](d{1,2})[.\/-]((y{4}|y{2})$))|(^(d{1,2})[.\/-](m{1,2})[.\/-]((y{4}|y{2})$))/gi.test(format); }

(added only "." in every character set [.\/-])

[flymans]

I fixed it myself, PR is waiting for review a month already.

[tux-tn]

@flymans sorry for the long delay🙏 I will review your PR today