Document how to configure Kotlin version resolution

[srinivasvsk]

Hello,
i tried to follow the latest documentation and the sample project. When i try to generate a kotlin project, it is erroring out with missing mapping for spring boot 2.5.6 with kotlin. Could you point to where the mapping can be configured and also if there is a way to just extend the whole configuration that would be great. Not able to find that information in docs

io.spring.initializr.metadata.InvalidInitializrMetadataException: No Kotlin version mapping available for 2.5.6.RELEASE
	at io.spring.initializr.metadata.InitializrConfiguration$Env$Kotlin.resolveKotlinVersion(InitializrConfiguration.java:424) ~[initializr-metadata-0.11.1.jar:na]
	at io.spring.initializr.generator.spring.code.kotlin.InitializrMetadataKotlinVersionResolver.resolveKotlinVersion(InitializrMetadataKotlinVersionResolver.java:39) ~[initializr-generator-spring-0.11.1.jar:na]

[wilkinsona]

start.spring.io uses a custom KotlinVersionResolver bean for this purpose: https://github.com/spring-io/start.spring.io/blob/a82ad12ca1ed372b4d95d9a092d41bf63ece9f1e/start-site/src/main/java/io/spring/start/site/extension/code/kotlin/ManagedDependenciesKotlinVersionResolver.java.

You can either define your own bean or update your application.yaml file to declare some mappings beneath initializr.env.kotlin.mappings.

[srinivasvsk]

thank you for the details!