Align with csvw spec

[mfenner]

Closely related, but more complex and web-focused: http://w3c.github.io/csvw/metadata/

[mfenner]

Also align with JSON Table Schema: http://dataprotocols.org/json-table-schema/

[jrovegno]

To enable the implementation of multiple descriptions, it would be necessary to define a key specific to the format that defines the type of metadata used.
For example (Reusing the @context key from csvw):

"@context":
- http://www.w3.org/ns/csvw
- "@language": en

"@context":
- http://frictionlessdata.io/specs/tabular-data-resource/
- "@language": en

But I am not sure that this generalization will help to massify the use or negatively affect the simplicity of the format.

References:

• https://discuss.okfn.org/t/w3c-csv-for-the-web-how-does-it-relate-to-data-packages/1715/3