stitch public url together from repo variables

.github/workflows/pages.yml

@@ -30,13 +30,9 @@ jobs:
       - name: Download and install Trunk binary
         run: wget -qO- https://github.com/thedodd/trunk/releases/latest/download/trunk-x86_64-unknown-linux-gnu.tar.gz | tar -xzf-
       - name: Build # build
-        # "${GITHUB_REPOSITORY#*/}" evaluates into the name of the repository
-        # using --public-url something will allow trunk to modify all the href paths like from favicon.ico to repo_name/favicon.ico .
-        # this is necessary for github pages where the site is deployed to username.github.io/repo_name and all files must be requested
-        # relatively as eframe_template/favicon.ico. if we skip public-url option, the href paths will instead request username.github.io/favicon.ico which
-        # will obviously return error 404 not found.
-        # run: ./trunk build --release --public-url "${GITHUB_REPOSITORY#*/}"
-        run: ./trunk build --release --public-url https://rims-code.github.io/crystal_angle/
+        run: ./trunk build --release --public-url $public_url
+        env:
+          public_url = "https://${{ github.repository_owner }}.github.io/${{ github.event.repository.name }}"
       - name: Deploy
         uses: JamesIves/github-pages-deploy-action@v4
         with: