chore(docs): Updated API Reference (v2) (#8686)

Automated changes by [create-pull-request](https://github.com/peter-evans/create-pull-request) GitHub action

www/apps/api-reference/specs/admin/code_samples/Shell/admin_payment-collections_{id}/delete.sh

@@ -0,0 +1,2 @@
+curl -X DELETE '{backend_url}/admin/payment-collections/{id}' \
+-H 'x-medusa-access-token: {api_token}'

www/apps/api-reference/specs/admin/code_samples/Shell/admin_payment-collections_{id}_mark-as-paid/post.sh

@@ -0,0 +1,6 @@
+curl -X POST '{backend_url}/admin/payment-collections/{id}/mark-as-paid' \
+-H 'x-medusa-access-token: {api_token}' \
+-H 'Content-Type: application/json' \
+--data-raw '{
+  "order_id": "{value}"
+}'