Update README

Update era5.py

0.7.0: Added ERA5 reanalysis data

Hot fix for interval in TimeSeriesEstimator

0.6.5: Fix interval in Generator; fix custom loss functions for model load compatibility

0.6.4: Fixed custom loss functions in model loading; added interval parameter to SeriesDataGenerator (beta)

0.6.3: Added anomaly correlation loss; minor fixes to examples

0.6.2: Updated CFSR data retrieval to include surface variables

0.6.1: Added data loading option to SeriesDataGenerator; fixed config parameters not saving for TFPadding layers

0.6.0: Added custom TF padding layers; fixed insolation in TimeSeriesEstimator

Updates to example scripts

Improvements to validate.py

0.5.4: Replaced AveragePadding with FillPadding

0.5.3: Added custom AveragePadding2D and AveragePadding3D layers

Minor fixes to validate.py and plotting