Private repos need explicit content read permissions to perform code checkout step.

[nikodevv]

Describe a bug

Private repos need explicit content read permissions to perform code checkout step. This is missing from the "minimal setup" instructions in README.

Without this permission, the checkout step will throw a

fatal: repository 'https://github.com/my/repo/' not found

Expected behavior

The "minimal setup" from readme doesn't work for private repos.

Details

• Action version: (any) this affects the checkout step in the setup documentation, not the jest-coverage-report-action source code.

• OS, where your action is running (windows, linux):

• action.yml file

  ```yml
  # Insert your action.yml file here. Don't forget to remove all sensitive information (e.g. tokens)
  ```
  

• Screenshots

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Additional context

[nikodevv]

oneliner fix: #281