feat(cli): add fabro docs to landing Set up section

Surfaces the docs website shortcut alongside the other onboarding
commands so new users can find the web docs without hunting through
`fabro help`.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

lib/crates/fabro-cli/src/landing.rs

@@ -36,6 +36,7 @@ pub(crate) fn print() {
             ("repo init", "Initialize Fabro in a repository"),
             ("server start", "Start the Fabro API server"),
             ("secret set", "Store a server-owned secret"),
+            ("docs", "Open the docs website in the browser"),
         ],
         cmd_width,
     );

lib/crates/fabro-cli/tests/it/cmd/fabro.rs

@@ -79,6 +79,7 @@ fn no_args_prints_curated_landing() {
       fabro repo init      Initialize Fabro in a repository
       fabro server start   Start the Fabro API server
       fabro secret set     Store a server-owned secret
+      fabro docs           Open the docs website in the browser
 
     Run workflows