Add topic modelling feature.

[muazhari]

Add topic modelling feature. Adding an interactive way to analyse corpus with topic modelling will be fun and useful.

Sources:

• https://towardsdatascience.com/interactive-topic-modeling-with-bertopic-1ea55e7d73d8

[ZanSara]

Hey @muazhari this won't be a priority for a while, but we're always open for contributions! 😊