Update Buildscript (#1199)

settings.gradle.kts

@@ -0,0 +1,20 @@
+pluginManagement {
+    repositories {
+        maven {
+            // RetroFuturaGradle
+            name = "GTNH Maven"
+            url = uri("https://nexus.gtnewhorizons.com/repository/public/")
+            mavenContent {
+                includeGroup("com.gtnewhorizons")
+                includeGroupByRegex("com\\.gtnewhorizons\\..+")
+            }
+        }
+        gradlePluginPortal()
+        mavenCentral()
+        mavenLocal()
+    }
+}
+
+plugins {
+    id("com.gtnewhorizons.gtnhsettingsconvention") version("2.0.6")
+}