[Feature request] Add a plugin for GitHub API tokens

[ninoseki]

GitHub API tokens has a unique format. So it can be detected through regex.

• API key format: (ghp|gho|ghu|ghs|ghr)_[A-Za-z0-9_]{36}
  • e.g. 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
  • ref. https://github.blog/2021-04-05-behind-githubs-new-authentication-token-formats/