feat: Attach files to release build (openscd#1620)

* create workflow for attaching files

* feat: attach core and plugin docs to build

---------

Co-authored-by: Sergio Alvarenga <s.alvarenga@sprinteins.com>

Author: salvar3nga

.github/workflows/attach-release-assets.yml

@@ -0,0 +1,38 @@
+on:
+  release:
+    types: [published]  # This triggers when a new release is published
+
+permissions:
+  contents: write
+
+name: attach-release-assets
+
+jobs:
+  attach-assets:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2.3.1
+      - name: Use Node.js 18.x
+        uses: actions/setup-node@v1
+        with:
+          node-version: "18.x"
+      - name: Install and Build OpenSCD
+        run: | 
+          npm i @nx/nx-linux-x64-gnu
+          npm clean-install
+          npm run-script build
+          npm run-script doc
+      - name: Copy Core Docs to OpenSCD
+        run: cp -R packages/core/doc packages/distribution/build/core-doc
+
+      - name: Copy Plugin Docs to OpenSCD
+        run: cp -R packages/plugins/doc packages/distribution/build/plugin-doc
+
+      - name: Compress files
+        run: tar -czf open-scd.tar.gz -C packages/distribution/build
+        
+      - name: Upload release files
+        run: gh release upload ${{ steps.release.outputs.tag_name }} open-scd.tar.gz
+        env: 
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}