CI: doc-publish-pr: Publish Rust docs alongside the rest

Detect if the doc build generated Rust docs, and include those in the
published documentation.

Signed-off-by: David Brown <david.brown@linaro.org>

.github/workflows/doc-publish-pr.yml

@@ -56,6 +56,8 @@ jobs:
     - name: Uncompress HTML docs
       if: steps.download-artifacts.outputs.found_artifact == 'true'
       run: |
+        echo "Artifacts present:"
+        ls -l *-output.tar.xz
         tar xf html-output/html-output.tar.xz -C html-output
         if [ -f api-coverage/api-coverage.tar.xz ]; then
           tar xf api-coverage/api-coverage.tar.xz -C api-coverage