Merge pull request rust-lang#233 from ehuss/update-mdbook

Update mdbook

Author: KodrAus

.github/workflows/deploy.yml

@@ -13,7 +13,7 @@ jobs:
 
       - name: Get mdBook
         run: |
-          export MDBOOK_VERSION="v0.4.2"
+          export MDBOOK_VERSION="v0.4.5"
           export MDBOOK_TARBALL="mdbook-${MDBOOK_VERSION}-x86_64-unknown-linux-gnu.tar.gz"
           export MDBOOK_URL="https://github.com/rust-lang/mdBook/releases/download/${MDBOOK_VERSION}/${MDBOOK_TARBALL}"
           curl -Lf "${MDBOOK_URL}" | tar -xz