mdBook Installation

So the way that mdBook was being installed in the Github actions thingy
was causing errors, I think I'm going to try and use Cargo to see what
happens.

.github/workflows/deploy-docs.yml

@@ -3,7 +3,7 @@ name: Deploy Documentation
 on:
   push:
     branches:
-      - main  # Change this if your default branch is different
+      - main
 
 jobs:
   deploy:
@@ -13,10 +13,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Install mdBook
-        run: |
-          curl -sSL https://github.com/rust-lang/mdBook/releases/latest/download/mdbook-linux-x86_64.tar.gz | tar -xz
-          chmod +x mdbook
-          mv mdbook /usr/local/bin/
+        run: cargo install mdbook --locked
 
       - name: Build mdBook
         run: mdbook build docs
@@ -25,5 +22,5 @@ jobs:
         uses: peaceiris/actions-gh-pages@v4
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
-          publish_dir: ./docs/book  # Adjust if your build output directory is different
+          publish_dir: ./docs/book
           publish_branch: gh-pages