Add `loadAfter` plugin setting

plugin-schema.json

 {
-  "$schema": "http://json-schema.org/draft-07/schema#",
-  "title": "JSON schema for a Grasscutter Plugin",
-  "type": "object",
-  "additionalProperties": true,
-  "definitions": {
-    "plugin-name": {
-      "type": "string",
-      "pattern": "^[A-Za-z\\d_.-]+$"
-    }
-  },
-  "required": [ "name", "description", "mainClass" ],
-  "properties": {
-    "name": {
-      "description": "The unique name of plugin.",
-      "$ref": "#/definitions/plugin-name"
-    },
-    "mainClass": {
-      "description": "The plugin's initial class file.",
-      "type": "string",
-      "pattern": "^(?!org\\.bukkit\\.)([a-zA-Z_$][a-zA-Z\\d_$]*\\.)*[a-zA-Z_$][a-zA-Z\\d_$]*$"
-    },
-    "version": {
-      "description": "A plugin revision identifier.",
-      "type": [ "string", "number" ]
-    },
-    "description": {
-      "description": "Human readable plugin summary.",
-      "type": "string"
-    },
-    "author": {
-      "description": "The plugin author.",
-      "type": "string"
-    },
-    "authors": {
-      "description": "The plugin contributors.",
-      "type": "array",
-      "items": {
-        "type": "string"
-      }
+    "$schema": "http://json-schema.org/draft-07/schema#",
+    "title": "JSON schema for a Grasscutter Plugin",
+    "type": "object",
+    "additionalProperties": true,
+    "definitions": {
+        "plugin-name": {
+            "type": "string",
+            "pattern": "^[A-Za-z\\d_.-]+$"
+        }
     },
-    "website": {
-      "title": "Website",
-      "description": "The URL to the plugin's site",
-      "type": "string",
-      "format": "uri"
+    "required": [
+        "name",
+        "description",
+        "mainClass"
+    ],
+    "properties": {
+        "name": {
+            "description": "The unique name of plugin.",
+            "$ref": "#/definitions/plugin-name"
+        },
+        "mainClass": {
+            "description": "The plugin's initial class file.",
+            "type": "string",
+            "pattern": "^(?!org\\.bukkit\\.)([a-zA-Z_$][a-zA-Z\\d_$]*\\.)*[a-zA-Z_$][a-zA-Z\\d_$]*$"
+        },
+        "version": {
+            "description": "A plugin revision identifier.",
+            "type": [
+                "string",
+                "number"
+            ]
+        },
+        "description": {
+            "description": "Human readable plugin summary.",
+            "type": "string"
+        },
+        "author": {
+            "description": "The plugin author.",
+            "type": "string"
+        },
+        "authors": {
+            "description": "The plugin contributors.",
+            "type": "array",
+            "items": {
+                "type": "string"
+            }
+        },
+        "website": {
+            "title": "Website",
+            "description": "The URL to the plugin's site",
+            "type": "string",
+            "format": "uri"
+        },
+        "loadAfter": {
+            "description": "Plugins to load before this plugin.",
+            "type": "array",
+            "items": {
+                "type": "string"
+            }
+        }
     }
-  }
 }
\ No newline at end of file

src/main/java/emu/grasscutter/plugin/PluginConfig.java

@@ -7,11 +7,13 @@ public final class PluginConfig {
     public String name, description, version;
     public String mainClass;
     public String[] authors;
+    public String[] loadAfter;
 
     /**
      * Attempts to validate this config instance.
      * @return True if the config is valid, false otherwise.
      */
+    @SuppressWarnings("BooleanMethodIsAlwaysInverted")
     public boolean validate() {
         return name != null && description != null && mainClass != null;
     }