Better documentation of metadata standard usage

Description of the issue

Question regarding usage of the Metadata.

I, for example, have the tool https://github.com/open-energy-data-server/open-energy-data-server which creates a database and can continuously crawl different datasets.

The question here is, how such a tool should use the standard best.

1. use the standard to annotate each crawler by providing a JSON file next to the crawler
   • who can use this?
   • is there some more readable format like yaml/toml instead of json allowed?
   • should this standard file be updated continuously for continuously updated end dates as described in #282 ?
2. add a metadata table
   • this is available when having database access
   • should this be stored as jsonb directly in the database? As the layout has multiple layers

Ideas of solution

While we do have a standard with the OEMetadata, it is still a little unclear how this should or can be used best.

The main idea is to provide interoperability between tools, so that one can parse the standard file to figure out what is or is not included.

So this issue is about my specific question and how this can best provide compatibility to other data sources (and how it can be used), but also about the requirement to have more documentation on the usage of the standard.

Workflow checklist

• I am aware of the workflow in CONTRIBUTING.md