start setting up Factorio Gradle mod

gradle-plugins/factorio-gradle/src/main/kotlin/dev/adamko/factorio_gradle/FactorioModPlugin.kt

@@ -0,0 +1,22 @@
+package dev.adamko.factorio_gradle
+
+import org.gradle.api.Plugin
+import org.gradle.api.Project
+import org.gradle.kotlin.dsl.create
+
+abstract class FactorioModPlugin : Plugin<Project> {
+
+  override fun apply(target: Project) {
+    target.createSettings()
+  }
+
+  private fun Project.createSettings(): FactorioModSettings {
+    return extensions.create<FactorioModSettings>(FACTORIO_GRADLE_EXTENSION_NAME).apply {
+
+    }
+  }
+
+  companion object {
+    const val FACTORIO_GRADLE_EXTENSION_NAME = "factorio"
+  }
+}

gradle-plugins/factorio-gradle/src/main/kotlin/dev/adamko/factorio_gradle/FactorioModSettings.kt

@@ -0,0 +1,16 @@
+package dev.adamko.factorio_gradle
+
+import org.gradle.api.file.DirectoryProperty
+import org.gradle.api.file.RegularFileProperty
+import org.gradle.api.provider.Property
+
+interface FactorioModSettings {
+
+  val factorioClientModsDirectory: DirectoryProperty
+
+  val steamExe: RegularFileProperty
+
+  val factorioGameSteamId: Property<String>
+
+  val factorioServerDataDirectory: DirectoryProperty
+}