docs: Add a note on docker for linux setup in prerequisites.

Author: tjholm

src/pages/getting-started/installation.mdx

@@ -12,10 +12,14 @@ Nitric relies on functionality from the following projects to help retrieve plug
 Please follow these links to the official installation steps for each.
 
 - [Git](https://git-scm.com/)
-- [Docker](https://docs.docker.com/get-docker/) _(deployments only)_
+- [Docker](https://docs.docker.com/get-docker/)
 - [Docker Buildx](https://github.com/docker/buildx/) _(deployments only)_
 - [Pulumi](https://www.pulumi.com/docs/cli/) _(for deployments, only needed if using the default providers)_
 
+<Note>
+When setting up docker on Linux be sure to follow the [post-installation steps](https://docs.docker.com/engine/install/linux-postinstall/) so you can run docker as a non-root user.
+</Note>
+
 ## Installing the Nitric CLI
 
 <InstallNitric>