Update 03.create_app_02.md

Replaced maverick to wrangler

Author: Jawon Song

docs/03.create_app_02.md

@@ -139,7 +139,7 @@ to expect one input fastq file as shown below:
   "name": "{{ agave.username }}-{{ app.name }}",
   "version": "{{ app.version }}",
   "executionType": "HPC",
-  "executionSystem": "hpc-tacc-maverick-{{ agave.username }}",
+  "executionSystem": "hpc-tacc-wrangler-{{ agave.username }}",
   "parallelism": "SERIAL",
   "deploymentPath": "{{ agave.username }}/apps/{{ app.bundle }}",
   "deploymentSystem": "data-sd2e-projects-users",