We should add a FAQ section for v2 that contains common doubts related to it.

It should atleast contain the following questions:

• What is the architecture of v2?
  That would contain the complete explaination of D1, D2, M and P layer with links to documentation.
• How to create TimeSeries class?
• What is the difference between TimeSeries, TimeSeriesDataset (from v1) and datamodule?
  This question is important to answer for those who are transitioning form v1 to v2 or are new to v2
• How to create and use datamodules?
• How to use pkg classes to perform fit, and predict.
• How to add a new model to the package