Allow configuring other data keys to be parsed as dates/content dates

[uncenter]

Is your feature request related to a problem? Please describe.

I come across the issue of and have dealt with personally wanting to use other keys besides date for content dates, but not having them work the same way as date does since it is treated specially. For example, having a published and edited fields instead of date for more granular metadata.

Describe the solution you'd like

Some kind of configuration API to control it. In #3652, I was thinking something like:

eleventyConfig.addPlugin(contentDates, {
  keys: ['date', 'published', 'edited']
});

But I'm not sure how best to keep it simple if it is still a core feature.

Describe alternatives you've considered

No response

Additional context

I hope this hasn't already been discussed. I searched among issues for a bit and didn't see anything and being involved in the community I haven't seen much linked around to on this matter.

[zachleat]

I think a lot of this could be achieved with computed data in the data cascade and luxon or https://github.com/11ty/parse-date-strings or whatever date library you want, no?

[uncenter]

Maybe a documentation tip would suffice? Seems to be a common enough issue it might warrant a configuration option but you're right it would be as simple as importing the parse function and applying it in a computed data file. Maybe the need for this has changed now that the default result of date is a native Date instead of a Luxon DateTime if I'm understanding correctly?

[uncenter]

I think a lot of this could be achieved with computed data in the data cascade and luxon or 11ty/parse-date-strings or whatever date library you want, no?

In #3926 @slightlyoff added that special values for dates such as "Last Modified" and "Created" are notable and tied to Eleventy internals, though yes for simpler cases using those aforementioned date parsing libraries could work.