Added X11 instructions for Mac
Link to Pluto.jl
Added placeholder sections
Replaced X-ray with X‐ray (unicode hyphen)
Fixed homepage URL
Added homepage link
Added WIP notice
Updated Home (markdown)
Tweaked section hierarchy
Specified the HEASoft version in the section heading
Docker overview and HEASoft installation on Mac
Docker placeholder
Link to relativistic accretion discs section
Started page about relativisitc accretion discs (wip)
Minor update to Julia link
Link to Julia section of wiki
Platform specific notes
Started Julia page
Modelling placeholder
X-ray spectroscopy placeholder
Relativistic disc placeholder
Initial Home page