Add read for Audacity label format - thx David :)

src/libse/SubtitleFormats/AudacityLabels.cs

@@ -0,0 +1,40 @@
+using Nikse.SubtitleEdit.Core.Common;
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+
+namespace Nikse.SubtitleEdit.Core.SubtitleFormats
+{
+    public class AudacityLabels : SubtitleFormat
+    {
+        public override string Extension => ".txt";
+
+        public override string Name => "Audacity labels";
+
+        public override void LoadSubtitle(Subtitle subtitle, List<string> lines, string fileName)
+        {
+            _errorCount = 0;
+            foreach (var line in lines)
+            {
+                var arr = line.Split('\t');
+                if (arr.Length == 3 &&
+                    double.TryParse(arr[0], NumberStyles.AllowDecimalPoint, CultureInfo.InvariantCulture, out var start) &&
+                    double.TryParse(arr[1], NumberStyles.AllowDecimalPoint, CultureInfo.InvariantCulture, out var end))
+                {
+                    subtitle.Paragraphs.Add(new Paragraph(arr[2], start * TimeCode.BaseUnit, end * TimeCode.BaseUnit));
+                }
+                else
+                {
+                    _errorCount++;
+                }
+            }
+
+            subtitle.Renumber();
+        }
+
+        public override string ToText(Subtitle subtitle, string title)
+        {
+            throw new NotImplementedException();
+        }
+    }
+}

src/libse/SubtitleFormats/SubtitleFormat.cs

@@ -651,6 +651,7 @@ namespace Nikse.SubtitleEdit.Core.SubtitleFormats
                 new MacCaption10(),
                 new Rdf1(),
                 new CombinedXml(),
+                new AudacityLabels(),
             };
         }