Update mdbook.yml

.github/workflows/mdbook.yml

@@ -34,6 +34,7 @@ jobs:
       - uses: actions/checkout@v4
       - name: Install mdBook
         run: |
+          cp -rf src-russian/* src/
           curl --proto '=https' --tlsv1.2 https://sh.rustup.rs -sSf -y | sh
           rustup update
           cargo install --version ${MDBOOK_VERSION} mdbook