docs: name the in-house SLS 2.0 data beside the public sets

The acknowledgement read as though the whole test corpus came from other people's beamlines. It does
not - in-house data collected at SLS 2.0 is tested alongside it. One clause, at the top of the
section; everything that follows still concerns the public data, which is the part that carries an
obligation to cite.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EFEJG6WBQv8th4UJFNe53N

docs/ACKNOWLEDGEMENT.md

@@ -25,12 +25,13 @@ This software uses Viridis, Magma and Inferno colormaps from Matplotlib under it
 
 ## Public diffraction data used for testing
 
-Jungfraujoch is tested against diffraction data collected on other people's beamlines, on
-detectors and in file formats we do not produce ourselves - most of it at other facilities, a
-few sets at the Swiss Light Source but not by this system. That data was collected and published
-by other people. Every dataset used, the DOI to cite for it, and
-the deposition it belongs to are listed in [EXTERNAL_TEST_DATA](EXTERNAL_TEST_DATA.md); we thank the
-depositors, and the repositories that make the data findable and citable.
+In addition to in-house datasets collected at SLS 2.0, Jungfraujoch is tested against public
+diffraction data collected on other people's beamlines, on detectors and in file formats we do not
+produce ourselves - most of it at other facilities, a few sets at the Swiss Light Source but not by
+this system. That data was collected and published by other people. Every dataset used, the DOI to
+cite for it, and the deposition it belongs to are listed in
+[EXTERNAL_TEST_DATA](EXTERNAL_TEST_DATA.md); we thank the depositors, and the repositories that make
+the data findable and citable.
 
 **[IRRMC](https://proteindiffraction.org/)**, the Integrated Resource for Reproducibility in
 Macromolecular Crystallography (Minor lab, University of Virginia), is the source of most of them.