Landing page light theme support

[BSoDium]

Here is a non exhaustive list of the elements of the page that look weird in light theme:

• Header illustration should be theme-specific:
  

• Resume link looks too contrasted and generally odd:
  

• Terminal colours are not contrasted enough:
  

• Icon glow looks very weird and should be softer:
  

• Project cards hover state is very poorly contrasted:
  

• Generated service colours should be adaptive and regenerated in light theme:
  

• Illustration glow should be softer