Create Gradle plugin

[suhtai]

To ease user installation and distribution we should create a Gradle plugin that sets up ksp (if not already set up) and provide a DSL to configure KopyKat options.

[serras]

My experience with this is that setting up a custom plug-in is as hard as setting up a KSP processor. But using ksp you get some niceties like option handling for free.

[suhtai]

I think it's handy for options as the user can autocomplete when using kts Gradle.

[suhtai]

For instance, we could have a set up like:

plugins {
  id("kopykat") // may need package, not sure
}

kopykat {
  generateMutableCopy = false
}

[aSemy]

I'd like to pick this up, I like Gradle :). Setting up some buildSrc convention plugins would help, so the Gradle publishing config can be applied on-demand, rather than in a subprojects{} block. I'll make a couple of PRs.

[aSemy]

Please take a look at #40 - instructions are in the PR :) There are some bugs to work out, but overall works when I test manually.