add kroki and antora-indexer extensions
diff --git a/antora-playbook.yml b/antora-playbook.yml
index 7a868b6..63b3f08 100644
--- a/antora-playbook.yml
+++ b/antora-playbook.yml
@@ -5,6 +5,12 @@
   sources:
   - url: ./../felix-site
 
+asciidoc:
+  attributes:
+    allow-uri-read: true
+  extensions:
+    - asciidoctor-kroki
+    - "@djencks/asciidoctor-antora-indexer"
 
 ui:
   bundle:
diff --git a/package.json b/package.json
index 0f46a3f..0cff57d 100644
--- a/package.json
+++ b/package.json
@@ -8,6 +8,8 @@
   "devDependencies": {
     "@antora/cli": "^2.3.3",
     "@antora/site-generator-default": "^2.3.3",
-    "@felix/felix-antora-ui": "./../felix-antora-ui"
+    "@felix/felix-antora-ui": "./../felix-antora-ui",
+    "asciidoctor-kroki": "^0.9.2",
+    "@djencks/asciidoctor-antora-indexer": "^0.0.4"
   }
 }