Fixed issue with the Pint data files not ending up in the package installation.

MANIFEST.in

 recursive-include dependencies/optimade-python-tools *.txt *.g *.py *.ini
 recursive-include nomad *.json *.j2 *.md *.yaml
+include nomad/units/*.txt
 include README.md
 include LICENSE.txt
 include requirements.txt
 include auto_complete_install.sh
-include setup.json
\ No newline at end of file
+include setup.json

docs/dev/setup.md

@@ -121,6 +121,7 @@ The NOMAD GUI requires static artifacts that are generated from the NOMAD Python
 ```
 nomad dev metainfo > gui/src/metainfo.json
 nomad dev searchQuantities > gui/src/searchQuantities.json
+nomad dev units > gui/src/units.js
 ./gitinfo.sh
 ```
 

setup.py

@@ -254,6 +254,7 @@ def setup_kwargs():
         install_requires=install_requires,
         extras_require=extras_require,
         include_package_data=True,
+        package_data={'nomad': ['units/*.txt']},
         python_requires='>=3.6',
         entry_points='''
             [console_scripts]

setup.sh

@@ -11,3 +11,4 @@ pip install -e .[all]
 
 nomad dev metainfo > gui/src/metainfo.json
 nomad dev search-quantities > gui/src/search-quantities.json
+nomad dev units > gui/src/units.js