Include optional property 'crossOrigin' in the API documentation for GeoImageOptions

[javier-lopez-1s]

Hi,
The class ol.source.GeoImage accepts in its constructor a property called crossOrigin, as can be seen in the line 45 of the source code:
https://github.com/Viglino/ol-ext/blob/master/src/source/GeoImage.js#L45
However, the API documentation for the object passed in the constructor, GeoImageOptions, does not detail this property. Could you please add it to the documentation?
The typescript declarations have already been updated to include this property. The pull request was Siedlerchr/types-ol-ext#189
Thanks

[Viglino]

Added in the last commit: 1f446b3