Gerber, Mike 4aed06a325 sbb_textline_detection: Preserve input PAGE info by merging segmentation results
ocrd_sbb_textline_detection used the output XML by main.py as is, and
– by doing this – threw away any input data from the input PAGE,
including the critical pc:AlternativeImage and the less important
pc:MetadataItem.

Fix this by merging the segmentation results into a file created from
the input file.

Also add a pc:MetadataItem processingStep about the segmentation
operation.
..
sbb_textline_detector sbb_textline_detection: Preserve input PAGE info by merging segmentation results
__init__.py 🧹 sbb_textline_detector: Use same structure as the other projects