Initial project setup for ElytraMace mod

Add Gradle build files, MIT license, and .gitignore. Implement ElytraMace client mod with keybindings for target selection and attack, including mixin for entity glowing effect. Register mod metadata and mixins configuration for Fabric loader.

settings.gradle

@@ -0,0 +1,9 @@
+pluginManagement {
+    repositories {
+        maven {
+            name = 'Fabric'
+            url = 'https://maven.fabricmc.net/'
+        }
+        gradlePluginPortal()
+    }
+}