[Feature]: Read and write schema language version at top of namespace YAML

[rly]

What would you like to see added to HDMF?

In preparation for supporting an update to the hdmf schema language, the language docs says that for the namespace file:

The beginning of the file must begin with a comment that starts with ‘hdmf-schema-language’ followed by a space and the version string of the specification language used by this namespace, e.g., hdmf-schema-language 2.2.0. Files without this comment are assumed to be defined using hdmf-schema-language 2.0.2.

We need to implement that to handle versioning correctly.

What solution would you like?

Write the version when writing spec YAML files. Read and store the version when reading spec YAML files.

Do you have any interest in helping implement the feature?

Yes.