FES2022 incorporated into README and tides extraction process

[fmemuir]

Implement FES2022 instead of older FES2014. According to AVISO, the main improvements compared to FES2014b are:

• Improved bathymetry in many shallow waters and coastal areas
• Globally enhanced and refined high-resolution mesh
• Globally enhanced altimeter and tidal gauges datasets
• Improved T-UGO model version for both the spectral and sequential modes
• Improved assimilation ensembles simulations
• Significant improvement in coastal areas

Not sure just how much impact this will make on tidal corrections for waterlines and filtering images for low/high tide to include/eliminate intertidal vegetation, but worth including for posterity.