chore: readme updates

Signed-off-by: Sam Gammon <sam@elide.dev>

README.md

@@ -14,6 +14,8 @@ This repository provides a [GitHub Action][0] to setup [Buildless][1] within you
 
 ## Usage
 
+> [Full documentation here](https://docs.less.build/docs/github-actions)
+
 **Install the latest Buildless CLI, add it to the `PATH`, and run the agent**
 ```yaml
   - name: "Setup: Buildless"
@@ -45,7 +47,7 @@ The full suite of available options are below.
 | `os`          | `string`     | (Current)                      | OS to target; defaults to current platform   |
 | `arch`        | `string`     | (Current)                      | Arch to target; defaults to current platform |
 | `agent`       | `boolean`    | `true`                         | Install and start the Buildless Agent        |
-| `apikey`      | `string`     | `${{ env.BUILDLESS_APIKEY }}` | Perform a self-test after installing         |
+| `apikey`      | `string`     | `${{ env.BUILDLESS_APIKEY }}`  | Explicitly set an API key                    |
 | `token`       | `string`     | `${{ env.GITHUB_TOKEN }}`      | GitHub token to use for fetching assets      |
 | `export_path` | `boolean`    | `true`                         | Whether to install Buildless onto the `PATH` |