Merge branch 'ch6' of https://github.com/hypocrasy/rCore-Tutorial-v3-comment into ch6

update build_doc

.github/workflows/build-doc.yml

@@ -16,10 +16,10 @@ jobs:
           rustup component add llvm-tools-preview
           rustup component add rust-src
           cd os
-          cargo doc --no-deps --verbose
-      - name: Deploy to Github Pages
+          cargo doc --document-private-items --verbose
+      - name: Push to gh-pages
         uses: peaceiris/actions-gh-pages@v3
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           publish_dir: ./os/target/riscv64gc-unknown-none-elf/doc
-          destination_dir: ${{ github.ref_name }}
+          destination_dir: ${{ github.ref_name }}