docs: Fix a typo & broken link (#678)

website/content/docs/getting-started/index.mdx

@@ -15,7 +15,7 @@ The examples in Getting Started all revolve around running in `dev mode`. There
 
 1. [Docker](https://docs.docker.com/get-docker/) is installed
 2. A route to download the [Postgres Docker image](https://hub.docker.com/_/postgres) is available or a local image cache is available
-3. A [Boundary binary](https://www.boundaryproject.io/downloads) in your \$PATH
+3. A [Boundary binary](https://www.boundaryproject.io/downloads) in your `$PATH`
 
 ## What is Dev Mode?