Adding page for promotion/credits docs (railwayapp#1067)

* adding credits pricing page

* note about referrals separate

* typo

* screenshots

Author: sarahkb125

content/docs/pricing/credits.md

@@ -0,0 +1,38 @@
+---
+title: Credits
+description: Learn how credits apply to your Railway account if part of a promotion.
+---
+
+If you are part of a credit promotion for Railway, this page covers how to activate and use your credits. This does not include the referral program as that functions differently - please see information [referrals here](/access/accounts#referrals).
+
+## Eligibility
+
+Credits and promotions only apply to new signups. If you already have an account, or signed up before navigating to the unique promotion link, the credits will not apply to you.
+
+## Activating Your Credits
+
+To activate your credits:
+
+1. Sign up for Railway using the unique link provided to you.
+2. Navigate to the [Plans page](https://railway.com/workspace/plans) to upgrade your plan to Hobby. On the page, you will see the name of your promotion if it applies to your account. For more information on available plans, see the [Pricing Plans](/pricing/plans) docs.
+
+<Image src="https://res.cloudinary.com/railway/image/upload/v1772038568/docs/promotion_plans_sftlji.png"
+alt="Promotion name on plans page"
+layout="intrinsic"
+width={800} height={468} quality={100} />
+
+3. Enter your credit card details. A credit card is required to cover any usage that exceeds your credit amount.
+
+You will see the credits applied to your next invoice.
+
+## Viewing Your Credits
+
+Once you have upgraded, you can view your credit and promotion details by navigating to [Workspace Settings > Billing](https://railway.com/workspace/billing). There you will find:
+
+- Whether a promotion code applies to your account
+- The credit value and duration of the promotion
+
+<Image src="https://res.cloudinary.com/railway/image/upload/v1772038568/docs/promotion_billing_xwgg9z.png"
+alt="Promotion details on billing page"
+layout="intrinsic"
+width={800} height={468} quality={100} />

src/data/sidebar.ts

@@ -66,6 +66,7 @@ export const sidebarContent: ISidebarContent = [
       makePage("Cost control", "pricing"),
       makePage("Committed spend", "pricing"),
       makePage("AWS Marketplace", "pricing"),
+      makePage("Credits", "pricing"),
     ],
   },
   // Enterprise