[Core] Common code snippet for defining config: locations and precedence

### Link to the page(s) on docs.getdbt.com requiring updates

Pages for any resource type that has configurations (like `enabled`, `meta`, etc.). This includes (but probably not limited to):
- https://docs.getdbt.com/reference/configs-and-properties#where-can-i-define-configs
- https://docs.getdbt.com/reference/model-configs#configuring-models
- https://docs.getdbt.com/reference/seed-configs
- https://docs.getdbt.com/reference/snapshot-configs
- https://docs.getdbt.com/reference/source-configs

### Tell us more about this update

[Here](https://docs.getdbt.com/reference/configs-and-properties#where-can-i-define-configs) and [here](https://docs.getdbt.com/reference/model-configs#configuring-models) have some content that is very similar to each other that could be abstracted into a snippet that can be shared.

#### Example 1

#### Example 2

Additionally, this content actually applies to other resources too that don't already include this information (like [seeds](https://docs-getdbt-com-git-ly-docs-issue-3239-dbt-labs.vercel.app/reference/seed-configs), [snapshots](https://docs-getdbt-com-git-ly-docs-issue-3239-dbt-labs.vercel.app/reference/snapshot-configs), etc).

So we should add that snippet to those pages too.

Finally, we should review if there are any other resource types that support `config()` like `enabled`, `meta`, etc. that should have this snippet added as well.

### Reviewers/Stakeholders/SMEs

`{{ this }}`

### Related GitHub issues

Noticed while reviewing https://github.com/dbt-labs/docs.getdbt.com/pull/5616.

Since this is larger scope that is also not urgent, created this separate issue.

### Additional information

_No response_