Create a template repository for starting a new project

1. Create a template repo in https://github.com/hiero-ledger/
2. Add project based on [example](https://github.com/hiero-ledger/hiero-gradle-conventions/tree/main/example)
3. Add to template repo:
    - Readme
    - basic GH actions
    - Dependabot config

Related to https://github.com/hiero-ledger/hiero-gradle-conventions/issues/260