[Feature] Example `dependencies.yml` for skills when running `dbt init`

### Is this your first time submitting a feature request?

- [x] I have read the [expectations for open source contributors](https://docs.getdbt.com/docs/contributing/oss-expectations)
- [x] I have searched the existing issues, and I could not find an existing issue for this feature
- [x] I am requesting a straightforward extension of existing dbt functionality, rather than a Big Idea better suited to a discussion

### Describe the feature

I was talking with @jasnonaz about https://github.com/dbt-labs/dbt-core/issues/12868, and he had the following idea:

As part of the dbt scaffolding that comes with `dbt init`, create a sample `dependencies.yml` file similar to this:

```yaml
# uncomment below to get all the awesome skills from the dbt Labs team

# skills:
# - git: "https://github.com/dbt-labs/dbt-agent-skills.git"
```

\* The exact verbiage to be determined (TBD).

The idea is that we want to make [`dbt-agent-skills`](https://github.com/dbt-labs/dbt-agent-skills) as discoverable and most likely to be installed as possible.

### Describe alternatives you've considered

_No response_

### Who will this benefit?

_No response_

### Are you interested in contributing this feature?

_No response_

### Anything else?

_No response_