Fix doc for with_first_found

the variables in with_first_found should be list rather than dict

lib/ansible/plugins/lookup/first_found.py

@@ -37,13 +37,13 @@ EXAMPLES = """
 - name: same copy but specific paths
   copy: src={{item}} dest=/some/file
   with_first_found:
-    files:
-      - foo
-      - "{{inventory_hostname}}
-      - bar
-    paths:
-      - /tmp/production
-      - /tmp/staging
+    - files:
+        - foo
+        - "{{inventory_hostname}}
+        - bar
+      paths:
+        - /tmp/production
+        - /tmp/staging
 
 - name: INTERFACES | Create Ansible header for /etc/network/interfaces
   template: