Add fast-follows to the AI onboarding flow (#34737)

Follow-up to https://github.com/zed-industries/zed/pull/33738.

Release Notes:

- N/A

---------

Co-authored-by: Bennet Bo Fenner <bennetbo@gmx.de>

crates/client/src/zed_urls.rs

@@ -30,3 +30,8 @@ pub fn start_trial_url(cx: &App) -> String {
 pub fn upgrade_to_zed_pro_url(cx: &App) -> String {
     format!("{server_url}/account/upgrade", server_url = server_url(cx))
 }
+
+/// Returns the URL to Zed's terms of service.
+pub fn terms_of_service(cx: &App) -> String {
+    format!("{server_url}/terms-of-service", server_url = server_url(cx))
+}