Signed-off-by: thxCode <thxcode0824@gmail.com>

learn collection link updated

Reference: https://github.com/hashicorp/terraform-provider-scaffolding-framework/issues/78

Updated via:

```shell
go mod edit -go=1.18
go mod tidy
go fix ./...
```

And textual file updates, such as the README.

Most of the content is inspired by existing content in https://github.com/hashicorp/terraform-provider-scaffolding.