Minor syntax error in readme example

[bitmagewb]

The example given has fail-on-missing-variables as an option. That returns an error if specified, which helpfully notes that it needs to be written with underscores instead: fail_on_missing_variables

Also, the readme mentions an example at https://github.com/Slidem/inplace-envsubst-action/blob/master/.github/workflows/test.yaml which returns a 404.

Thanks for putting this together, did just what I needed!

[Slidem]

Thanks for pointing that out, will modify the README