parse Notes String
Parse notes data from a string (.notes format).
File format: tab-separated "start_time end_time freq_hz label" per line. Example:
4.899410 5.224489 138.591315 Ṇ
4.980680 7.047256 145.986691 SContent copied to clipboard
Return
Parsed notes data, or null if parsing failed
Parameters
content
String containing notes data