graphcast intro description needs ERA5 link fixing

In the opening description on https://github.com/google-deepmind/graphcast there's a sentence "Full model training requires downloading the [ERA5](https://www.ecmwf.int/en/forecasts/datasets/reanalysis-datasets/era5) dataset, available from [ECMWF](https://www.ecmwf.int/)."

Please can you update the first link in that sentence, i.e. the ERA5 URL, to https://www.ecmwf.int/en/forecasts/dataset/ecmwf-reanalysis-v5

Thanks