The scoring-similarity plugin does not provide an example file for the property scoring.similarity.stopword.file.
This is an issue for a number of reasons, namely
- A user does not know what it is meant to look like, and
- We always check of this file and will throw an exception if it is not found, this may not be picked up by the user until much later.
I suggest a simple fix here, simply include the standard English stop words taken from Lucene's StopAnalyzer. The comments will help people to easily customize the list to whatever they require.