[DOC] - Add a glossary of terms

[iameskild]

Given the number of services and technologies involved in a Nebari deployment, a glossary of terms would be a handy tool enabling all of us (users, devs, etc) to more precisely communicate.

Some other OS projects that have glossaries include:

• https://zero-to-jupyterhub.readthedocs.io/en/latest/resources/glossary.html
• https://kubernetes.io/docs/reference/glossary/?fundamental=true

References to the above might be a good place to start as well.

[pavithraes]

Quick note for future reference, we can include: profiles, namespaces, administrator, user, VPN, VPC ...