Update labRemote README with GCC requirements, TOC, etc

This MR updates the README to, among other things, specify clearly the required gcc version (C++ standard).

Also adds table of contents, and cleans up a bit of other things.

Note1: This MR is related to !137 (closed), and can be considered as a re-scoped follow-up on the discussion had in relation to it.

Note2: Why is there a section devoted to ProbeStation. This seems as though it should be an entirely separate labRemote-app...