Start of an SRT subtitle group parser.

srt_grou_parser_start.swift

let srtGroupParser = Int.parser(isSigned: false) // The sequence number.
	.skip(Newline()) // ❌ “Generic struct ‘Newline’ requires the types ‘Substring.Element’
	// (aka ‘Character’) and ‘UTF8.CodeUnit’ (aka ‘UInt8’) be equivalent.”
	.take(timecodeLineParser)
	.skip(Newline())
	// …