CurrentHill USA military assets pack (#461)

* usa military assets pack

* minor fixes to have missiles

* tweak nasams 3

* fix preset groups bug

* adjust b-21 name

* Update faction.py

bugfixes will go in a different branch

pydcs_extensions/__init__.py

@@ -37,6 +37,7 @@ from .uh60l import *
 from .vietnamwarvessels import *
 from .chinesemilitaryassetspack import *
 from .russianmilitaryassetspack import *
+from .usamilitaryassetspack import *
 
 
 def load_mods() -> None: