The `.forward()`/etc. shape API

There is the nn.Module.forward(...) method. So, it’s “standardized”.

Each concrete .forward(...)'s documentation has its return shape (formula).

Is there an API/a project of API of the .get_forward_shape(...) method to get it programatically?

/cc @albanD, @ptrblck , thanks.

I’ve reposted at the issues.