🥰 [FEATURE]能否添加一个多边形挖洞的功能

[xiaonanfeng]

💻 Features description [Please make everyone to understand it]

可将已经绘制的多边形进行挖洞

🏞 What problem does this feature solve

🧐 What does the proposed API look like

🚑 Any additional [like screenshots]

it looks like this : https://viglino.github.io/ol-ext/examples/interaction/map.interaction.drawhole.html