There is no such documentation because they are all seperate tools.
RSpec is a standalone testing tool, it consists of a group of gems, by default if you use rspec-rails you’ll automatically use rspec-core rspec-mocks and rspec-expectations which provider the runner, mocking / double tools, and expectation matchers. You can customise the later two parts with other gems but you’re best of looking at their documentation of how to be used with rspec-core if thats the route you are taking.
Cucumber is a BDD descriptive testing framework, we use it to provide documentation via relish and to prevent an entirely dog-food test suit. (E.g it verifies that our documentation works through reproducible examples). Cucumber can use rspec-mocks and rspec-expectations, but this is optional and up to your configuration.
Relish is a cucumber documentation host.
Mini-Test is a replacement for test-unit, whilst you can use rspec-mocks and rspec-expectations with it, this is a-typical. Most people use rspec or mini-test, not both.
AutoTest is an old auto test watcher. It can be safely turned off if you are upgrading an old project, its function is/was to watch your files and run the changed tests to shorten the TDD cycle but has been replaced with more modern tools like guard, zeus, etc.