[Feature] Top-level changelog

### 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

It would be handy to have a top-level changelog like the following that links to the individual changelogs:

## Changelogs

For information on prior releases, see the individual changelogs:

* [`dbt-adapters`](https://github.com/dbt-labs/dbt-adapters/blob/main/dbt-adapters/CHANGELOG.md)
* [`dbt-tests-adapter`](https://github.com/dbt-labs/dbt-adapters/blob/main/dbt-tests-adapter/CHANGELOG.md)
* [`dbt-athena-community`](https://github.com/dbt-labs/dbt-adapters/blob/main/dbt-adapters/CHANGELOG.md) (❌ there is no changelog for this adapter)
* [`dbt-athena`](https://github.com/dbt-labs/dbt-adapters/blob/main/dbt-athena/CHANGELOG.md)
* [`dbt-bigquery`](https://github.com/dbt-labs/dbt-adapters/blob/main/dbt-bigquery/CHANGELOG.md)
* [`dbt-postgres`](https://github.com/dbt-labs/dbt-adapters/blob/main/dbt-postgres/CHANGELOG.md)
* [`dbt-redshift`](https://github.com/dbt-labs/dbt-adapters/blob/main/dbt-redshift/CHANGELOG.md)
* [`dbt-snowflake`](https://github.com/dbt-labs/dbt-adapters/blob/main/dbt-snowflake/CHANGELOG.md)
* [`dbt-spark`](https://github.com/dbt-labs/dbt-adapters/blob/main/dbt-spark/CHANGELOG.md)

This would be especially useful for anyone trying to orient to the monorepo. Or that expected the changelog for `dbt-adapters` to be at the top level (and didn't realize there is a `dbt-adapters` subdirectory).

### 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_