Add support for C++ in Protobuf Generator Script

### Feature Request: Add Support for C++

#### Description:
The Protobuf Generator Script currently supports generating code for Go, Ruby, Java, and C#. This feature request aims to extend support to C++.

#### Requirements:
- Update the script to handle `.proto` files and generate C++ code.
- Use `namely/protoc-all` to ensure consistent generation.
- No specific package option (`option cpp_package`) is required for C++.

#### Expected Behavior:
- The script should detect `.proto` files and generate C++ code when the `cpp` option is selected.
- Generated files should be stored in the `proto/generated/` directory.

#### Steps to Implement:
1. Modify the PowerShell script to add a case for `cpp`:
- No validation for package-specific options (unlike Go or Java).
- Ensure the Docker command for `namely/protoc-all` includes `-l cpp`.
2. Test the updated script to ensure it generates valid C++ files.

#### Resources:
- [namely/protoc-all documentation](https://github.com/namely/docker-protoc)
- [Protocol Buffers documentation](https://developers.google.com/protocol-buffers)

#### Contribution Guidelines:
We welcome contributions! If you'd like to work on this feature, please comment below or open a pull request referencing this issue.

#### Labels:
`enhancement`, `help wanted`, `good first issue`

Start by locating the PowerShell generator script and reviewing its existing language cases and Docker invocation. Add the cpp selection alongside the current generators, then run it against the repository's .proto files and verify that C++ output is created in proto/generated/ using namely/protoc-all.

Written by the indexing model from the issue text.