Added improved build and bundling using gulp.

Updated npm build targets.

.eslintrc.json

 {
   "env": {
     "es6": true,
-    "browser": true
+    "browser": true,
+    "node": true
   },
   "extends": "eslint:recommended",
   "parserOptions": {

gulpfile.js

+// Gulp.js configuration
+"use strict";
+
+const gulp = require("gulp");
+const replace = require("gulp-replace");
+const zip = require("gulp-zip");
+const del = require("del");
+
+const dir = {
+    src: ".",
+    build: "./release/",
+};
+
+// PHP settings
+const php = {
+    src: [dir.src + "/**/*.php", "!node_modules/**", "!release/**"],
+    build: dir.build,
+};
+
+const parcel = {
+    src: "./build/release/**",
+    build: dir.build + "build/release/",
+};
+
+function clean() {
+    return del(dir.build + "**", { force: true });
+}
+
+function copyPHP() {
+    return gulp
+        .src(php.src)
+        .pipe(
+            replace(
+                "$GLOBALS['build'] = 'debug';",
+                "$GLOBALS['build'] = 'release';"
+            )
+        )
+        .pipe(gulp.dest(php.build));
+}
+
+function copyParcel() {
+    return gulp.src(parcel.src).pipe(gulp.dest(parcel.build));
+}
+
+function zipBuild() {
+    return gulp
+        .src(dir.build + "**")
+        .pipe(zip("knowledge-space.zip"))
+        .pipe(gulp.dest(dir.build));
+}
+
+function copyDefaultSpace() {
+    return gulp
+        .src("datasets/space.json")
+        .pipe(gulp.dest(dir.build + "datasets/"));
+}
+
+function copyEditorIcons() {
+    return gulp
+        .src("editor/images/**/*.png")
+        .pipe(gulp.dest(dir.build + "editor/images/"));
+}
+
+function copyBackground() {
+    return gulp
+        .src("backgrounds/background_4.jpg")
+        .pipe(gulp.dest(dir.build + "backgrounds/"));
+}
+
+exports.build = gulp.series(
+    clean,
+    copyPHP,
+    copyParcel,
+    copyDefaultSpace,
+    copyEditorIcons,
+    copyBackground,
+    zipBuild
+);

package.json

@@ -2,7 +2,7 @@
   "name": "knowledge-space",
   "version": "1.0.0",
   "description": "A Wordpress-Plugin to display knowledge in a graph-structured way.",
-  "main": "index.js",
+  "source": "index.js",
   "debug": "build/debug/graph.js",
   "release": "build/release/graph.js",
   "targets": {
@@ -13,20 +13,13 @@
     "release": {
       "distDir": "build/release/",
       "sourceMap": false,
-      "optimize": true,
-      "includeNodeModules": [
-        "three",
-        "3d-force-graph",
-        "force-graph"
-      ],
-      "isLibrary": true,
-      "context": "node"
+      "optimize": true
     }
   },
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1",
     "watch": "parcel watch index.js",
-    "build": "parcel build index.js --target release"
+    "build": "parcel build index.js --target release && gulp build"
   },
   "repository": {
     "type": "git",
@@ -43,7 +36,11 @@
   "devDependencies": {
     "@babel/core": "^7.14.8",
     "@babel/eslint-parser": "^7.14.9",
+    "del": "^6.0.0",
     "eslint": "^7.32.0",
+    "gulp": "^4.0.2",
+    "gulp-replace": "^1.1.3",
+    "gulp-zip": "^5.1.0",
     "parcel": "^2.0.0-rc.0",
     "prettier": "^2.3.2"
   },