Attempt faster generation of mdbook using precompiled bins.

.github/workflows/book.yml

@@ -31,12 +31,17 @@ jobs:
             - name: Install ghp-import and mdbook
               run: |
                 pip install ghp-import
-                cargo install mdbook
-                export PATH="$HOME/.cargo/bin:$PATH"
-                cargo install --git "https://github.com/lzanini/mdbook-katex"
-                cargo install --git "https://github.com/badboy/mdbook-toc"
-                cargo install --git "https://github.com/badboy/mdbook-mermaid"
-                sudo apt -y install make
+                sudo apt -y install make wget
+                wget "https://github.com/badboy/mdbook-toc/releases/download/0.10.0/mdbook-toc-0.10.0-x86_64-unknown-linux-gnu.tar.gz"
+                wget "https://github.com/lzanini/mdbook-katex/releases/download/v0.2.18/mdbook-katex-v0.2.18-x86_64-unknown-linux-gnu.tar.gz"
+                wget "https://github.com/badboy/mdbook-mermaid/releases/download/v0.12.3/mdbook-mermaid-v0.12.3-x86_64-unknown-linux-gnu.tar.gz"
+                wget "https://github.com/rust-lang/mdBook/releases/download/v0.4.22/mdbook-v0.4.22-x86_64-unknown-linux-gnu.tar.gz"
+                for i in *.tar.gz; do
+                    tar xf "$i"
+                    rm -f "$i"
+                done
+                mkdir -p "$HOME/bin"
+                export PATH="$HOME/bin:$PATH"
 
             - name: Compile and publish the book
               run: |