fix app build name & add pkgx config

package.json

@@ -155,7 +155,7 @@
   },
   "main": "./dist-electron/main.js",
   "build": {
-    "appId": "org.timesafari.app",
+    "appId": "app.timesafari",
     "productName": "TimeSafari",
     "directories": {
       "output": "dist-electron-packages"

pkgx.yaml

@@ -0,0 +1,5 @@
+dependencies:
+  - gradle
+  - java
+
+# other dependencies are discovered via package.json & requirements.txt & Gemfile (I'm guessing).