Add some guidelines/estimates for how long time dynasor run will take
It could be nice for users to have some guidelines and estimates for how long time a dynasor run will take.
For example
- time scales linearly with number of qpts
- time scales linearly with max_frames
- 10,000 atoms 10,000 frames with isotropic q-point samplings, 1000qpts, takes XYZ hours