Rename zed.dev/settings to zed.dev/account (#15636)

This PR renames the links to the `zed.dev/settings` page to the
`zed.dev/account`.

Some of these spots will likely link out to a marketing page later.

Release Notes:

- N/A

crates/collab/src/api/billing.rs

@@ -153,7 +153,7 @@ async fn create_billing_subscription(
             quantity: Some(1),
             ..Default::default()
         }]);
-        let success_url = format!("{}/settings", app.config.zed_dot_dev_url());
+        let success_url = format!("{}/account", app.config.zed_dot_dev_url());
         params.success_url = Some(&success_url);
 
         CheckoutSession::create(&stripe_client, params).await?
@@ -261,7 +261,7 @@ async fn manage_billing_subscription(
             after_completion: Some(CreateBillingPortalSessionFlowDataAfterCompletion {
                 type_: stripe::CreateBillingPortalSessionFlowDataAfterCompletionType::Redirect,
                 redirect: Some(CreateBillingPortalSessionFlowDataAfterCompletionRedirect {
-                    return_url: format!("{}/settings", app.config.zed_dot_dev_url()),
+                    return_url: format!("{}/account", app.config.zed_dot_dev_url()),
                 }),
                 ..Default::default()
             }),
@@ -278,7 +278,7 @@ async fn manage_billing_subscription(
 
     let mut params = CreateBillingPortalSession::new(customer_id);
     params.flow_data = Some(flow);
-    let return_url = format!("{}/settings", app.config.zed_dot_dev_url());
+    let return_url = format!("{}/account", app.config.zed_dot_dev_url());
     params.return_url = Some(&return_url);
 
     let session = BillingPortalSession::create(&stripe_client, params).await?;