[ENH] Use Better Labeling Tool for Intents and Entities

[AlexanderNeumann]

1. Motivation - The usability of the current editor could be enhanced by using modern solutions like brat, doccano or INCEpTION.
   It is difficult for non computer scientists to create such annotations with the current editor.

2. Specification - You would have to change the editor and exchange it with one of the mentioned solutions or maybe another one.

3. Finalised state - It would be nice if the user can use such annotation tools and there is a translation to markdown/yaml which can be used by rasa (I would prefer yaml since it is used by the latest version of rasa)