Add description for `--check` flag to CLI build options help

### Is your feature request related to a problem? Please describe.

The description for the `--check` option in the CLI is provided in the documentation,[^1] but it is not available in the build options that can be checked with `--help`.

[^1]: https://the-guild.dev/graphql/codegen/docs/config-reference/codegen-config#cli-flags

### Describe the solution you'd like

The description for the `--check` option should be provided with `--help`.

### Describe alternatives you've considered

_No response_

### Any additional important details?

_No response_