Departments CRUD endpoints

Create the basic endpoints for the Departments table using the already existing schema. The id field is autogenerated, so for the creating we only need a name and a desciption.
Optionally it should all be only used by administrators (using the roles guard).

Start by locating the existing Departments schema and nearby CRUD endpoint patterns. Implement create, read, update, and delete operations using the autogenerated id, name, and description fields; verify each endpoint against the existing schema and determine whether the roles guard should restrict them to administrators.

Written by the indexing model from the issue text.