Update (or edit readme) for OpenLayers 10

[david-morris]

The readme states this is only compatible up to OpenLayers 9. 9->10 doesn't have many breaking changes.

Does this library use getFeaturesInExtent() or 'get' expression type hints? If not, the readme can be updated. If so, maybe an update is in order.

[Dominique92]

You are right, no major changes nor issues with OL ^10.1

We don't use getFeaturesInExtent nor type hints. Why should we note it in readme ?

[david-morris]

Why should we note it in readme?

It would be convenient for outsiders like me to judge the health of the OpenLayers community and the extension.