Potentially improve line detection

[QazCetelic]

You might not be aware about this, since the lines are currently split using /(?:\r\n|\r|\n)/, but WhatsApp text exports use different newlines for user newlines and newlines after messages.

For example, for the following conversation:

[22-01-20 10:00:00] Bob: This is spread
over multiple lines
[22-01-20 10:01:00] Alice: This is the next message

The newlines are as follows:

[22-01-20 10:00:00] Bob: This is spread\n
over multiple lines\r\n
[22-01-20 10:01:00] Alice: This is the next message\r\n

This could potentially be used to improve message detection in fringe cases.