Javascript library for text annotation

[FlorianJacta]

What would that feature address
A user requested a way to annotate text. It is used for NLP applications.

Description of the ideal solution

Related discussion: The specific problem is to annotate training data for a Rasa chatbot. The syntax follows this pattern:
[<entity-text>]{"entity": "<entity name>", "role": "<role name>", "group": "<group name>", "value": "<entity synonym>"}.

Example:
What's the balance on my [credit card account]{"entity":"account","value":"credit"}

The idea might be to add something like a selector that allows the user to mark characters and invoke a function on them (like opening up a form that contains information about the marked characters). In the example above, it could work like this:

1. The GUI visualizes a data frame containing sentences
2. The user selects "credit card account" in an example sentence
3. The GUI opens a small window with a form to add the values for "entity", "role", "group", and "value"
4. The user fills in the values and clicks a "Save" button inside that small window.
5. The GUI calls a function that handles this dataset (e.g., replaces the sentence in a modified data frame with the annotated sentence)

From this use case, this library could work:
https://github.com/recogito/recogito-js
It can be tested here:
https://recogito.github.io/recogito-js/

Acceptance Criteria

• Ensure new code is unit tested, and check code coverage is at least 90%
• Propagate any change on the demos and run all of them to ensure there is no breaking change
• Ensure any change is well documented