Changes mainly regarding intercept range

[HaneulCheong]

• Changes regarding intercept range
  • Closes #40.
  • Now interceptRange is defined for the following units:
  • Fighter (8)
  • Jet Fighter (10)
  • Fighter Drone (8)
  • Anti-Aircraft Gun (2)
  • Mobile SAM (3)
  • Attack Helicopter (1) - Can possibly be changed to 2
  • Destroyer (2)
  • Carrier (2)
  • All the other units now cannot intercept air units. - See https://github.com/SpacedOutChicken/DeCiv-Redux/pull/41#issuecomment-1067167474
• Cannot build Civilian Convoys when below -10 Happiness
  • i.e. Fixed one of the global uniques using Settler instead of Civilian Convoy
• Added missing commas
  • Doesn't matter to be honest since Atavism will be removed, but still.
• Removed unnecessary comments
  • Those are now included in the official base game wiki.
  • Also reformatted ToDoList.md using headings.
• Fixed a typo and added headings to Credits.md

[HaneulCheong]

Like, all Personnel units?

Edit: Jet Boat and Arroyo Machine Gun cannot have that promotion due to their unit type, yet both of them are Personnel units. Should they still be able to anti-air?

[HaneulCheong]

• Redefined intercept range for Personnel units
  • I just added to all of them since more conditions and exceptions might lead to more future bugs. Consistency, you know.