Add provenance header to summary for nicer readbility

Author: hynek

action.yml

@@ -114,6 +114,11 @@ runs:
       shell: bash
       working-directory: ${{ inputs.path }}
 
+    - name: Add GitHub build provenance header
+      if: ${{ inputs.attest-build-provenance-github == 'true' }}
+      shell: bash
+      run: echo -e '\n### GitHub Build Provenance' >> $GITHUB_STEP_SUMMARY
+
     - name: Attest GitHub build provenance
       if: ${{ inputs.attest-build-provenance-github == 'true' }}
       uses: actions/attest-build-provenance@v1