Manual: Add subsection on lxplus installation

Jens Kroeger requested to merge jekroege/corryvreckan:manual_lxplus into master

This MR comprises:

  • short subsection on lxplus (took sentence about setup script from further above). Now it's more promiment + link to project website with step-by-step instructions
  • fix linebreaks in MacOS tips
Edited by Jens Kroeger

Merge request reports