Remove plugins.gradle and factor into common extension

settings.gradle

@@ -1,5 +1,37 @@
+import java.nio.file.Paths
+import java.nio.file.Path
+
 rootProject.name = 'org.apollo'
 include ':cache'
 include ':game'
+include ':game:plugin'
+include ':game:plugin-testing'
 include ':net'
 include ':util'
+
+def pluginDirs = [
+    rootProject.projectDir.toPath().resolve("game/plugin"),
+]
+
+def processPluginDir(Path pluginDir) {
+    if (pluginDir.toFile().exists()) {
+        def pluginFileFinder = new FileNameFinder();
+        def pluginFiles = pluginFileFinder.getFileNames(pluginDir.toString(), "**/*.gradle");
+
+        pluginFiles.each { filename ->
+            def path = Paths.get(filename)
+            def parentPath = path.parent
+
+            if (parentPath == pluginDir) {
+                return
+            }
+
+            def relativePath = pluginDir.relativize(parentPath)
+            def pluginName = relativePath.toString().replaceAll("/", ":")
+
+            include ":game:plugin:$pluginName"
+        }
+    }
+}
+
+pluginDirs.each { processPluginDir(it) }