Render docs for experimental namespace

[oruebel]

The docs for the new experimental namespace are currently not being rendered on ReadTheDocs. This will likely require some changes to the setup of how the docs are generated and/or the hdmf-docutils.

[mavaylon1]

@oruebel Is this still needed?

[oruebel]

Yes, this is still an issue. The problem is that the docs only process the main namespace hdfm-common

hdmf-common-schema/common/namespace.yaml

Line 3 in b3e48fc

- name: hdmf-common

while the second namespace hdfm-experimental is being ignored:

hdmf-common-schema/common/namespace.yaml

Line 28 in b3e48fc

- name: hdmf-experimental

As a result, ExternalResources and EnumData are not being rendered on the page, e.g., as part of the type hierarchy:

https://hdmf-common-schema.readthedocs.io/en/latest/format.html#type-hierarchy

Fixing this for the docs, will require some trickery on the either the setup here in conf.py or potentially on the hdfm-docutils to support multiple namespaces.