Option to group YAML under a single key

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Is your feature request related to a problem? Please describe. Sometimes the YAML key names created by the plugin are duplicates of YAML keys that I'd like to use in the document for something else, e.g. id:.

Describe the solution you'd like It would be convenient to have an option to group the YAML under a single customisable key, by default mediaDB: for example. This way any YAML keys that the plugin outputs can't be duplicates of any that I've created at the root level of my front matter. I'd hope such an option would also take effect when copying to clipboard (#107).

Thanks.