Make releaseDateColumn true by default

[waldyrious]

Is your feature request related to a problem? Please describe.
Currently, ~339 out of ~355 entries in products/ (95%) use releaseDateColumn: true. Clearly this is something the community finds broadly valuable and applicable to the vast majority of cases. It's counterproductive to force all those entries to manually specify this field, and the surprising default adds an extra barrier for new contributors.

Describe the solution you'd like
The releaseDateColumn field should default to true so that it doesn't need to be manually specified.

Describe alternatives you've considered
N/A

Additional context
I've searched the repository and didn't find any previous discussions of this.

[captn3m0]

Happy to accept a PR for this. This would also involve some changes to our validation, and documentation.

Defaults can be applied via _config.yml, similar to other attributes.

[waldyrious]

Great! I'll prepare a PR as soon as my current one #6645 is merged :)