docs: edits

packages/web/src/content/docs/docs/cli.mdx

@@ -5,12 +5,20 @@ description: opencode CLI options and commands.
 
 import { Tabs, TabItem } from "@astrojs/starlight/components"
 
-The opencode CLI accepts commands as documented on this page. You can run any of the available commands to interact with opencode programmatically.
+The opencode CLI by default starts the [TUI](/docs/tui) when run without any arguments.
+
+```bash
+opencode
+```
+
+But it also accepts commands as documented on this page. This allows you to interact with opencode programmatically.
 
 ```bash
 opencode run "Explain how closures work in JavaScript"
 ```
 
+
+
 ---
 
 ## Commands