Add commented out example of a useful post start hook

[naseemkullah]

This post start lifecycle hook will configure templates if not using logstash/filebeat, but rather something does not support managing templates (at the time of this commit) such as fluent bit.

Will come in handy for others to have it commented out there.

• Chart version not bumped (the versions are all bumped and released at the same time)
• [n/a] README.md updated with any new values or changes
• [n/a] Updated template tests in ${CHART}/tests/*.py
• [n/a] Updated integration tests in ${CHART}/examples/*/test/goss.yaml

[elasticmachine]

Since this is a community submitted pull request, a Jenkins build has not been kicked off automatically. Can an Elastic organization member please verify the contents of this patch and then kick off a build manually?

[jmlrt]

LGTM, thanks for this example