Add slide deck for JavaLand

Author: hannotify

.gitmodules

@@ -105,3 +105,6 @@
 [submodule "_slides/javas-concurrency-journey-continues/jfokus-2026"]
 	path = _slides/javas-concurrency-journey-continues/jfokus-2026
 	url = https://github.com/hannotify/javas-concurrency-journey-continues
+[submodule "_slides/javas-concurrency-journey-continues/javaland-2026"]
+	path = _slides/javas-concurrency-journey-continues/javaland-2026
+	url = https://github.com/hannotify/javas-concurrency-journey-continues

_data/events.yml

@@ -66,6 +66,8 @@
   appearances:
     - id: javas-concurrency-journey-continues
       sessionPageUrl: https://meine.doag.org/events/javaland/2026/agenda/#eventDay.1773183600
+      slides:
+        source: local
 
 - id: jfokus-2026
   name: JFokus