Merge pull request nf-core#2485 from ewels/sig-add-blogpost-link

SIG index page - add link to announcement blog post.

src/pages/special-interest-groups/index.astro

@@ -9,7 +9,13 @@ groups = groups
 
 <ListingLayout
     title="Special Interest Groups"
-    description="nf-core Special Interest Groups are groups of community members who are interested in a particular aspect of nf-core, such as pipelines, tools, or community engagement."
+    description=`
+        nf-core Special Interest Groups are groups of community members who are interested
+        in a particular aspect of nf-core, such as pipelines, tools, or community engagement.
+        </p><p>
+        <i class="fa-solid fa-circle-info me-2"></i>
+        To find out more about Special Interest Groups, read the <a href='/blog/2024/special_interest_groups'>announcement blog post</a>.
+    `
     specialInterestGroups={groups}
     displayStyle={[
         { name: 'grid', icon: 'fa-regular fa-grid-2' },