Add rustdoc output to manual site

.github/workflows/deploy_docs.yml

@@ -13,6 +13,15 @@ jobs:
     steps:
       - uses: actions/checkout@v2
 
+      - uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: 1.54.0
+          override: true
+      - uses: actions-rs/cargo@v1
+        with:
+          command: doc
+
       - name: Setup mdBook
         uses: peaceiris/actions-mdbook@v1
         with:
@@ -22,7 +31,10 @@ jobs:
         run: mdbook build
         working-directory: manual
 
-      - name: Deploy to GitHub pages🚀
+      - name: Add rustdoc output
+        run: cp -r target/doc manual/book
+
+      - name: Deploy to GitHub pages
         uses: JamesIves/github-pages-deploy-action@4.1.6
         with:
           branch: gh-pages