Clarify help text on events

Nobody has claimed this yet.

Following troubleshooting an issue for Events on mass.gov:

A user indicated that they could reuse an existing event and create a new one from it by adding a new date and time in the Complex date and time text field.

The area reads:

> Complex event date and time
> Enter the date and time in this field only if they cannot be expressed in a strictly numeric way.
**> If entered, this will override both the date AND time below.** (emphasis mine)

So when the user asked why the event wasn't showing up on their page(s), it was because they didn't change the exact drop-down items for the start/end times and dates. They believed that the "override" sentence made it so that they didn't need to do that each time they wanted to create an event. Of course, the event did not appear on the page because it had already occurred (in the past); the "override" did not work.

I'm submitting this for the team to potentially consider looking at this language to clarify what the text field is being used for. I acknowledge that the previous sentence, _Enter the date and time in this field only if they cannot be expressed in a strictly numeric way_, does explain the function a bit. Maybe some shadow text (e.g., We will be open from sunrise to sunset) would be helpful instead of/in addition to help text?

Start with the issue's quoted help text for the “Complex event date and time” field and review how the current wording could be misunderstood. Done means proposing clearer help or shadow text that explains when the field applies and how it relates to the numeric date and time fields; no files or tests are identified in the payload.

Written by the indexing model from the issue text.