DOC Update deploy docs workflow for multiversion (#175)

* update github workflow deploy docs

* update github workflow deploy docs

.github/workflows/deploy-docs.yml

@@ -22,6 +22,14 @@ jobs:
     steps:
       - uses: actions/checkout@v2
 
+      - name: Get TAG
+        run: echo "TAG=${{ github.ref_name }}" >> $GITHUB_ENV
+
+      - name: Get DOC_DIR
+        run: |
+          DOC_DIR="$(cut -d '.' -f 1,2 <<< "$TAG")"
+          echo "DOC_DIR=${DOC_DIR:1}".x >> $GITHUB_ENV
+
       - name: Set up Qt
         uses: tlambert03/setup-qt-libs@v1
 
@@ -49,11 +57,22 @@ jobs:
           working-directory: doc
           run: make html
 
-      - name: Deploy docs 🚀
+      - name: Deploy dev docs 🚀
+        uses: JamesIves/[email protected]
+        with:
+          branch: gh-pages
+          folder: doc/_build/html
+          target-folder: dev
+          clean: true
+
+      - name: Deploy stable docs 🚀
         uses: JamesIves/[email protected]
+        if: startsWith(env.TAG, 'v')
         with:
           branch: gh-pages
           folder: doc/_build/html
+          target-folder: ${{ env.DOC_DIR }}
+          clean: true
 
       - name: Cache
         uses: actions/cache@v2