Resolve build errors & cleanup structure (#2334)

.github/workflows/prettify.yml

@@ -0,0 +1,18 @@
+name: Prettify
+on: push
+jobs:
+  prettier:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v2
+      with:
+        ref: ${{ github.head_ref }}
+
+    - name: Prettify code
+      uses: creyD/prettier_action@v3.3
+      with:
+        prettier_options: --write **/*.java
+        commit_message: 'Prettify code'
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}