configuration is invalid

Hello,

When running tfplugindocs inside my terraform plugin I have this error:

```
tfplugindocs.exe generate
rendering website for provider "terraform_ccc_provider"
exporting schema from Terraform
compiling provider "terraform_ccc_provider"
using Terraform CLI binary from PATH if available, otherwise downloading latest Terraform CLI binary
running terraform init
Error executing command: unable to generate website: configuration is invalid
```

I cannot get any information on what is invalid and what this tool is expecting. Would be nice to have more informations on this kind of errors.

Can you help me?

Regards