Update docker-install.md fixing broken link (#4948)

## What are you changing in this pull request and why?
A link in the markdown file resulted in a 404 error. The corresponding
link is fixed in this merge request.

## Checklist
- [ ] Review the [Content style
guide](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/content-style-guide.md)
so my content adheres to these guidelines.
- [ ] For [docs
versioning](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/single-sourcing-content.md#about-versioning),
review how to [version a whole
page](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/single-sourcing-content.md#adding-a-new-version)
and [version a block of
content](https://github.com/dbt-labs/docs.getdbt.com/blob/current/contributing/single-sourcing-content.md#versioning-blocks-of-content).
- [ ] Add a checklist item for anything that needs to happen before this
PR is merged, such as "needs technical review" or "change base branch."

website/docs/docs/core/docker-install.md

@@ -11,7 +11,7 @@ You might also be able to use Docker to install and develop locally if you don't
 
 ### Prerequisites
 * You've installed Docker. For more information, see the [Docker](https://docs.docker.com/) site.
-* You understand which database adapter(s) you need. For more information, see [About dbt adapters](docs/core/installation-overview#about-dbt-data-platforms-and-adapters).
+* You understand which database adapter(s) you need. For more information, see [About dbt adapters](/docs/core/installation-overview#about-dbt-data-platforms-and-adapters).
 * You understand how dbt Core is versioned. For more information, see [About dbt Core versions](/docs/dbt-versions/core).
 * You have a general understanding of the dbt, dbt workflow, developing locally in the command line interface (CLI). For more information, see [About dbt](/docs/introduction#how-do-i-use-dbt).