Document various options for error handling

# Summary

Workflows has a lot of knobs about error handling such as retries, timeouts, ignoring errors, etc... There should be a comprehensive documentation explaining when to use which features. Off the top of my head:

* retryStrategy
* resubmitPendingPods
* activeDeadlineSeconds
* timeout (new feature)
* continueOn
* depends syntax

Start by reviewing the existing Workflows documentation and the behavior of retryStrategy, resubmitPendingPods, activeDeadlineSeconds, timeout, continueOn, and depends syntax. Organize guidance explaining when each error-handling option should be used and how the options relate to one another; done means the listed features are covered comprehensively.

Written by the indexing model from the issue text.