Add docs/definitions of elements/metadata tags from NWB schema

These YAML files define the structure of the elements of the NWB file: https://github.com/NeurodataWithoutBorders/nwb-schema/blob/dev/core/nwb.file.yaml#L111

It would be good to parse these and load the doc fields to add as hover over/tool tips on the corresponding element in the NWBE GUI, e.g. Experimenter, Stimulus, Device, etc....

A lot of the docs deal with how to structure an NWB file rather than just explaining what the field/group is used for (so developer documentation aot user documentation...), but it would be better than nothing for completely new users looking through the data...

Start with the NWB schema file core/nwb.file.yaml around the referenced definitions and review how its doc fields describe elements such as Experimenter, Stimulus, and Device. Then locate the NWBE GUI’s corresponding element views; done means those definitions are parsed and shown as hover text or tooltips for new users.

Written by the indexing model from the issue text.