Add guide on tool integrations

[stephprince]

When labeling issues, I saw that there were several issues proposing to add tools to the glossary where the comments indicate that we wanted to test the tool ourselves. I think it could be helpful to formalize what this testing process looks like so other tool developers know what we are looking for in an integration.

This kind of guide could provide a brief overview of what we are looking for in some of these topics:

• does it support read and/or write of NWB files (and do written files pass validation/inspection)
• is there example code and documentation on where NWB is integrated
• does it work when testing with different NWB files (would be helpful to provide some specific examples to use)
• any other general suggestions to make integrations more robust (are specific versions of NWB required, are specific fields/data types expected, are extensions used and documented)

This guide is helpful for adding tools to the glossary, but seems primarily focused on sharing the tool after initial development vs. providing guidelines during development.