Add Kotlin DSL

[jamierocks]

Resolves #24

    val mappings = MappingSetDsl.create {
        klass("a") {
            deobf = "Example"
            extension(EXTRA, "Hello, World!")
        }
        klass("b") {
            deobf = "Demo"

            field("g") {
                deobf = "name"
            }

            method("h", "(Z)Ljava/lang/String;") {
                deobf = "getName"
                param(0) {
                    deobf = "propagate"
                }
            }

            klass("d") {
                deobf = "Inner"
            }
        }
    }

Huge thanks to @pie-flavor for helping me to navigate my way through Kotlin 👍

todo

• Generate javadocs jar, with Kappa
• Document fully
• Unit test, with Kotlintest

[DenWav]

Probably too late now, but might be worth breaking API compatibility to fix it. The lorenz-dsl-groovy module provides the org.cadixdev.lorenz.dsl package and this PR provides the org.cadixdev.lorenz.dsl.kotlin package. In order for these libraries to be compatible with JPMS modules can't provide the same package, so that's okay, but it would be nice if the lorenz-dsl-groovy module provided the org.cadixdev.lorenz.dsl.groovy package instead for consistency - and that would open the option for something like a lorenz-dsl project which could do something similar but with lambda expressions and provide near-DSL like support for Java.

[jamierocks]

@DemonWav I'll eventually re-locate the Groovy one as per your suggestion, I'm sure that was my intention.

[jamierocks]

Alright, I've relocated the Groovy DSL. Hopefully I'll find some time over the next week or so to finish this off.