Option to extract a subset of splits

[cerpintext]

split	split time	sgmnt time	best time
1	3:35.02	3:35.02	3:32.05
2	5:26.50	1:51.48	1:45.20
3	7:58.51	2:32.01	2:32.01
4	9:45.32	1:46.81	1:44.20
5	11:43.76	1:58.44	1:50.34
6	13:23.54	1:39.78	1:28.70
7	14:37.63	1:14.08	1:09.52
8	16:25.28	1:47.64	1:45.18

if you have the above lss-data and want to practice individual parts of it (ie. splits 3-5), you could extract those splits and make it available for download in to its own lss-file:

split	split time	sgmnt time	best time
3	2:32.01	2:32.01	2:32.01
4	4:28.82	1:46.81	1:44.20
5	6:17.26	1:58.44	1:50.34

this would be useful for making segment comparison splits for comparison data during segment practice, especially with longer runs with more points of data to handle manually.

[Webcretaire]

Thanks for the issue, it would be a nice feature to have indeed