docs: update openapi

Author: alexey-yarmosh

Diff for: public/v1/components/headers.yaml

@@ -17,3 +17,11 @@ components:
       description: The number of seconds until the limit is reset.
       schema:
         type: integer
+    CreditsCost:
+      description: Then number of credits consumed by the request. Shown only when credits are involved.
+      schema:
+        type: integer
+    CreditsRemaining:
+      description: The number of remaining credits for that user. Shown only when credits are involved.
+      schema:
+        type: integer

Diff for: public/v1/components/responses.yaml

@@ -117,6 +117,10 @@ components:
           $ref: 'headers.yaml#/components/headers/RateLimitRemaining'
         X-RateLimit-Reset:
           $ref: 'headers.yaml#/components/headers/RateLimitReset'
+        X-Credits-Cost:
+          $ref: 'headers.yaml#/components/headers/CreditsCost'
+        X-Credits-Remaining:
+          $ref: 'headers.yaml#/components/headers/CreditsRemaining'
       content:
         application/json:
           schema: