[Doc]: update xcdat Regridding doc and link to/from xESMF

[jypeter]

Describe your documentation update

xESMF website

I have just noticed that there is an old link from the xESMF Other geospatial regridding tools page to Regridder in UV-CDAT. You may want to ask them to link to the xCDAT home page, or to your Horizontal Regridding page

xCDAT Horizontal Regridding

• xCDAT Horizontal Regridding page mentions xESMF at the beginning of the page, but you have to scroll down to sections 4 and 5 to find actual links to the the xESMF documentation. Maybe you could (also) have a link to the xESMF: Universal Regridder for Geospatial Data website closer to the top

• the links you use for xESMF (including your xarray.Dataset.regridder.horizontal page) use https://pangeo-xesmf.readthedocs.io/en/latest/, but I have seen that the same documentation is also available at https://xesmf.readthedocs.io/en/stable/. Both links seem to have the same content, but the one without pangeo- may be more canonical?

[tomvothecoder]

Thanks for opening this GitHub issue, @jypeter. Pull requests are always welcome!