wrong class in "i18n/ja.yaml"

[n-arakawa]

Class string for gdoc_heart in footer_build_with may be wrong.
Compare with one in "en.yaml", class="icon gdoc_heart" should reed class="gdoc-icon gdoc_heart".

footer_build_with: >
  <a href="https://gohugo.io/" class="gdoc-footer__link">Hugo</a> でビルドしています。
  <svg class="icon gdoc_heart"><use xlink:href="#gdoc_heart"></use></svg>

[Robert Kaussow]

Thanks for your report!