docs: add todo for ansible ioc-start

ansible/playbooks/ioc-start.yml

@@ -1,3 +1,6 @@
+# TODO: ansible seems to be very slow on this machine
+# each step takes quite a while (e.g. cloning repo, which
+# is significantly faster on other machines).
 ---
 - name: Start an IOC
   hosts: vserv