fix(blocklists): add explicit DocCard/DocCardGrid imports for MDX v3

Author: ziracmo

crowdsec-docs/unversioned/blocklists/getting_started.mdx

@@ -6,6 +6,8 @@ eyebrow: Blocklists · 02
 
 import { CIcon } from "@coreui/icons-react";
 import { cilCheckCircle } from "@coreui/icons";
+import DocCard from '@site/src/components/docs/DocCard';
+import DocCardGrid from '@site/src/components/docs/DocCardGrid';
 
 New to CrowdSec blocklists? Read the [Introduction](/u/blocklists/intro) first to understand how they work and the available tiers. Then choose one of the two paths below — most people pick **one or the other, not both**.