Adds include and linkings for plugins

plugin/index.js

@@ -0,0 +1,11 @@
+const path = require("path");
+
+const NODEGUI_ROOT = path.resolve(__dirname, "..");
+const CMAKE_HELPER_DIR = path.resolve(NODEGUI_ROOT, "config");
+const CMAKE_HELPER_FILE = path.resolve(CMAKE_HELPER_DIR, "plugin.cmake");
+
+module.exports = {
+  CMAKE_HELPER_FILE,
+  CMAKE_HELPER_DIR,
+  NODEGUI_ROOT
+};