Remove 'coming soon' from Billing (custom code reference)

Author: oliwolff1

src/content/docs/design/customize-with-code/understand-page-design.mdx

@@ -265,7 +265,7 @@ Shown after primary authentication when MFA is required or being set up.
 - `(mfa_use_recovery_code)` – Enter a recovery code if unable to use other MFA methods.
 - `(mfa_view_recovery_codes)` – View and save MFA recovery codes.
 
-### Billing (coming soon)
+### Billing
 
 Pages related to choosing a plan and making a payment.
 
@@ -339,4 +339,4 @@ export const pageSettings = {
 };
 ```
 
-This allows you to have fine grained control over what your pages can access.
+This allows you to have fine grained control over what your pages can access.