Add missing alt attributes for images to make rake test pass

[yasulab]

生成された HTML の静的解析テスト ($ bundle exec rake test) を実行し、出てきたエラーを修正しました! 🛠💨✨

Before

※ クリックするとテスト結果レポートの詳細が表示されます。

$ bundle exec rake test

$ bundle exec rake test

...


Incremental build: disabled. Enable with --incremental
      Generating...
       Jekyll Feed: Generating feed for posts
                    done in 0.174 seconds.

Auto-regeneration: disabled. Use --watch to enable.
Running 5 checks (Favicon, Images, Links, OpenGraph, Scripts) in ["_site"] on *.html files ...


Checking 21 internal links
Checking internal link hashes in 1 file
Ran on 18 files!


For the Images check, the following failures were found:

* At _site/events/index.html:168:

  image /img/events/saikyo-coderdojo.webp does not have an alt attribute

* At _site/events/index.html:197:

  image /img/contests/cover.webp does not have an alt attribute

* At _site/index.html:201:

  image /img/top/about-coderdojo/coderdojo-logo-transparent.webp does not have an alt attribute

* At _site/index.html:220:

  image /img/top/about-coderdojo/coderdojo-logo-transparent.webp does not have an alt attribute

* At _site/index.html:221:

  image /img/top/about-coderdojo/dojocon.webp does not have an alt attribute

* At _site/index.html:226:

  image /img/top/about-coderdojo/dojocon.webp does not have an alt attribute

* At _site/index.html:255:

  image /img/top/inspire-next/exhibit.webp does not have an alt attribute

* At _site/index.html:257:

  image /img/top/inspire-next/fire-transparent.webp does not have an alt attribute

* At _site/index.html:266:

  image /img/top/inspire-next/fire-transparent.webp does not have an alt attribute

* At _site/index.html:284:

  image /img/top/inspire-next/exhibit.webp does not have an alt attribute

* At _site/index.html:360:

  image /img/top/background1.webp does not have an alt attribute

* At _site/index.html:429:

  image /img/top/background2.webp does not have an alt attribute

* At _site/index.html:471:

  image /img/top/background3.webp does not have an alt attribute

* At _site/index.html:603:

  image /img/top/background4.webp does not have an alt attribute

* At _site/index.html:619:

  image /img/top/background5.webp does not have an alt attribute

* At _site/sessions/keynote1/index.html:154:

  image /img/sessions/profile/miyajima-kirie.webp does not have an alt attribute

* At _site/sessions/keynote2/index.html:154:

  image /img/sessions/profile/komiyama-rieko.webp does not have an alt attribute


HTML-Proofer found 17 failures!

After

$ bundle exec rake test

...

Incremental build: disabled. Enable with --incremental
      Generating...
       Jekyll Feed: Generating feed for posts
                    done in 0.172 seconds.

Auto-regeneration: disabled. Use --watch to enable.
Running 5 checks (Favicon, Images, Links, OpenGraph, Scripts) in ["_site"] on *.html files ...

Checking 21 internal links
Checking internal link hashes in 1 file
Ran on 18 files!

HTML-Proofer finished successfully.

TIPS

.github/workflows/test.yml にある以下のコメントアウトを解除すると、CI 上で自動的に検知できるようになります。ただ迅速にデプロイしたい場面もあると思うので（その場合は静的解析テストが重荷になることもあるので）今回のように不定期に手動で実行して、結果を確認しても良さそうです 💭

    - name: 🔧 Build & Test
      run: |
        ...
        # SKIP_BUILD=true       bundle exec rake test
        # NOTE: サイトが仕上がったら、上記テストを走らせると自動検知できる。
        #       ただ初期は自動検知の通知が多すぎるので手動で実行するのが吉。
        ...

[mucho613]

ありがとうございます！ LGTM 👍️