[build] Restructure to composite build

conventions/settings.gradle.kts

@@ -0,0 +1,18 @@
+plugins {
+    id("dev.panuszewski.typesafe-conventions") version "0.9.0"
+}
+
+dependencyResolutionManagement {
+	repositories {
+		gradlePluginPortal()
+	}
+	versionCatalogs {
+		create("libs") {
+			from(files("../gradle/libs.versions.toml"))
+		}
+	}
+}
+
+include("helpers")
+
+rootProject.name = "tweed5-conventions"