FSH slicing warnings

[oliveregger]

we have a lot of FSH slicing warnings (Sushi?)

ushi: File: /Users/oegger/Documents/github/ch-elm/input/fsh/examples/1-NeisseriaGonorrhoeae/1-DocumentReference.fsh (00:00.000 / 00:11.432, 59Mb)
Sushi: Line: 67 (00:00.000 / 00:11.433, 59Mb)
Sushi: warn Sliced element Composition.section is being accessed via numeric index. Use slice names in rule paths when possible. (00:00.535 / 00:11.968, 59Mb)
Sushi: File: /Users/oegger/Documents/github/ch-elm/input/fsh/examples/2Doc-ChlamydiaTrachomatis.fsh (00:00.000 / 00:11.969, 59Mb)
Sushi: Line: 48 (00:00.000 / 00:11.969, 59Mb)
Sushi: warn Sliced element Composition.section is being accessed via numeric index. Use slice names in rule paths when possible. (00:00.000 / 00:11.969, 59Mb)
Sushi: File: /Users/oegger/Documents/github/ch-elm/input/fsh/examples/2Doc-ChlamydiaTrachomatis.fsh (00:00.000 / 00:11.970, 59Mb)
S

would be good to have them removed to reduce the noise (at least for the one we can).