The S1000D XML schemas are not provided in this repository. They can be
downloaded from http://s1000d.org/Downloads/Pages/S1000DDownloads.aspx

Place the S1000D XML schemas you want to convert inside this directory,
with the following path structure:
```
schemas/S1000D_[major]-[minor]/xml_schema_flat/[schema].xsd
```

Then run `sh build.sh`.