Add Antarctica Map (#544)

## Description:
This PR adds the new Deglaciated Antarctica map(suggested by Backn). It
has 9 nations - most of the country territorial claims on the continent
and the "Penguin Empire".

fixes #545 

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced
- [x] I understand that submitting code with bugs that could have been
caught through manual testing blocks releases and new features for all
contributors

## Please put your Discord username so you can be contacted if a bug or
regression is found:

Nikola123

---------

Co-authored-by: Loymdayddaud <145969603+TheGiraffe3@users.noreply.github.com>

src/scripts/generateTerrainMaps.ts

@@ -24,6 +24,7 @@ const maps = [
   "Japan",
   "KnownWorld",
   "FaroeIslands",
+  "DeglaciatedAntarctica",
 ];
 
 const removeSmall = true;