Provide result details for missing words

[MichaelRoeder]

User story

As a user of Palmetto, I rely on the tool to get a lot of numbers that rate my topics. However, the API only provides the final result. Since the online index comes with some limitations (e.g., only lemmas are indexed, no other word forms) it would be good to get some more details. A major concern is that words which haven't been found in the index may have a big impact on the final result without that I as a user have a chance to know that.

Solution

• Add a warning field to the response which allows a better interaction with the user (e.g., give warnings if a word was not found at all)
• Add per-word statistics (e.g., word count) to enable the user to identify words that were not found or that have a very low count

Implementation details

• Adapt the internal API to allow complex results
• Add another service URL to the endpoint for getting complex result objects (as JSON); keep the old plain endpoint for backwards compatibility
• Design a JSON response object with the necessary information