Merge branch 'jdaw/adjust-ns-definition' into 'master'

Clarify ns definition in docs

See merge request machine-learning/dorado!833

(cherry picked from commit 69a625d)

e970fa9 Clarify ns definition in docs
3138c08 update ns documentation to clarify what is included and excluded

documentation/SAM.md

@@ -26,8 +26,8 @@
 | ------ | -----------------------------------------------------------|
 | RG:Z:  | `<runid>_<basecalling_model>_<barcode_arrangement>`        |
 | qs:i:  | mean basecall qscore rounded to the nearest integer        |
-| ns:i:  | the number of samples in the signal prior to trimming      |
 | ts:i:  | the number of samples trimmed from the start of the signal |
+| ns:i:  | the basecalled sequence corresponds to the interval `signal[ts : ns]` <br /> the move table maps to the same interval. <br /> note that `ns` reflects trimming (if any) from the rear <br /> of the signal. |
 | mx:i:  | read mux                                                   |
 | ch:i:  | read channel                                               |
 | rn:i:  | read number                                                |