Describes the cause and action for error messages.
Error Message(English):
activity overview
Showing an overview of your activity on your profile - GitHub Help
https://help.github.com/en/articles/showing-an-overview-of-your-activity-on-your-profile
Viewing contributions on your profile - GitHub Help
https://help.github.com/en/articles/viewing-contributions-on-your-profile
Profile activity overview - The GitHub Blog
https://github.blog/changelog/2018-08-24-profile-activity-overview
GitHubを楽しく使おう - Qiita
https://qiita.com/mochisuna/items/8cdab33f2f903817cc92
GitHub Enterprise ver.2.15のご紹介! | ブログ | マクニカネットワークス
https://www.macnica.net/github/blog_20181207.html
GitHub on Twitter: "Show off your contribution history in new ways with ...
https://twitter.com/github/status/1033081196308295681
https://twitter.com/github/status/1033081196308295681
はてなブックマーク - Profile activity overview | The GitHub Blog
http://b.hatena.ne.jp/entry/s/blog.github.com/changelog/2018-08-24-profile-activity-overview/
選べる!寿司ランチ始めました | クラウドワークス エンジニア採用サイト ...
https://crowdworks.co.jp/engineers/13