WebP: improving support

The WebP format is now supported by all major browsers, is a new Web standard, and is much more efficient than PNG or JPG (much lighter and better quality files).

Photoshop can export to WebP, but the operation is (unnecessarily) complicated: You have to change the color method, but it could do it automatically when exporting. WebP is not among the options in the "Export" function, you have to use "Save As", but it doesn't always work, then you have to try "Save a Copy". These are all nonsense.

Please add full support for WebP format!