Build for docker and aws lambda please

[suntong]

Thanks for this wonderful build tool first of all, and I wish it can be used to build for docker and aws lambda as well.

• From Default optimization differs when building docker images #84 it looks like building for docker is available, just not documented.
• For aws lambda, please take a look the following two docker building scripts if you will,
  • https://github.com/TOKIUM/image-magick-aws-lambda-layer/blob/main/Dockerfile
  • https://github.com/RikudouSage/LambdaPhpImagickLayer/blob/master/Dockerfile

Please consider. Thanks