Document with dependencies are available

[hauleth]

While trying to solve N-th Prime task I wanted to use 2 libraries:

• data-ordlist (to use unionAll and minus)
• relude (to use !!? operator)

But the task failed with error that it cannot fetch them from the repository due to lack of network connection. That is pretty obvious why there is no network in the test instance, but it makes it a little bit painful that there is no list of the libraries that are available during tasks solving.

[petertseng]

Duplicate of #1045