Update README.md (#181)

* Update README.md

Author: afinetooth

README.md

@@ -14,7 +14,7 @@ The action's step needs to run after your test suite has outputted an LCOV file.
 
 | Name                  | Requirement | Description |
 | --------------------- | ----------- | ----------- |
-| `github-token`        | _optional_ | Default: `${{ github.token }}`. Can be also used this way: `github-token: ${{ secrets.GITHUB_TOKEN }}`; Coveralls uses this token to verify the posted coverage data on the repo and create a new check based on the results. It is built into Github Actions and does not need to be manually specified in your secrets store. [More Info](https://help.github.com/en/actions/configuring-and-managing-workflows/authenticating-with-the-github_token)|
+| `github-token`        | _required_ | Default if not specified: `${{ github.token }}`. Can be also specified this way: `github-token: ${{ secrets.GITHUB_TOKEN }}`; Coveralls uses this token to verify the appropriate repo at Coveralls and send any new status updates based on your coverage results. This variable is built into Github Actions, so __do not add it to your secrets store__. [More Info](https://help.github.com/en/actions/configuring-and-managing-workflows/authenticating-with-the-github_token)|
 | `file`        | _optional_ | Default: all coverage files that could be found. Local path to the coverage report file produced by your test suite. An error will be thrown if no file was found. This is the file that will be sent to the Coveralls API. Leave empty if you want to combine many files reports. |
 | `format`              | _optional_ | Force coverage report file format. If not specified, coveralls will try to detect the format based on file extension and/or content. Possible values: `lcov`, `simplecov`, `cobertura`, `jacoco`, `gcov`, `golang`, `python`. See also [actual supported coverage report formats list](https://github.com/coverallsapp/coverage-reporter#supported-coverage-report-formats). |
 | `flag-name`           | _optional (unique required if parallel)_ | Job flag name, e.g. "Unit", "Functional", or "Integration". Will be shown in the Coveralls UI. |