Fix trivial change to index.html

Author: Andrej730

.github/workflows/bonsai-docs.yml

@@ -27,7 +27,7 @@ jobs:
           cp -r _build/html/* bonsaibim_org_docs/
           printf "docs.bonsaibim.org" > bonsaibim_org_docs/CNAME
           touch bonsaibim_org_docs/.nojekyll
-          sed -i 's/<\/head>/<!-- Bonsai -->\n<\/head>/' bonsaibim_org_docs/index.html
+          echo "<!-- bonsaibim generated -->" >> bonsaibim_org_docs/index.html
           git -C bonsaibim_org_docs add .
           git -C bonsaibim_org_docs commit -m "Build"
           git -C bonsaibim_org_docs push