Adding an actual Hello World file

What it says on the tin.
Revert "Adding an actual Hello World file"

This reverts commit 7468ab4b7146ae23bb087f83bcdca1cbd6b5d649.
Revert "Revert "Adding an actual Hello World file""

This reverts commit cfa717319e99f92c042e92b167b69a4879494d0e.
(I'm actually adding it this time)