Add a GitHub Action for uploading sources to Crowdin

.github/workflows/crowdin.yml

@@ -0,0 +1,21 @@
+name: crowdin
+on:
+  push:
+    branches:
+      - master
+jobs:
+  upload-sources:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Install crowdin-cli
+        run: |
+          wget https://github.com/crowdin/crowdin-cli/releases/download/3.2.1/crowdin-cli.zip
+          echo "953e8714ca114b21eabd8f588d4b1c9e8ac1d1df3621176fc08ce611200f3108  crowdin-cli.zip" | sha256sum -c
+          unzip crowdin-cli.zip -d crowdin-cli
+      - name: Upload to Crowdin
+        env:
+          CROWDIN_SETTINGS: "${{ secrets.CROWDIN_SETTINGS }}"
+        run: |
+          echo "$CROWDIN_SETTINGS" > ~/.crowdin.yml
+          java -jar ./crowdin-cli/3.2.1/crowdin-cli.jar push -c ~/.crowdin.yml -b master