Support F-84G Thunderjet mod v2.5.7.01 (#8)

* Implemented support for the VSN F-84G Thunderjet version 2.5.7.01

game/theater/start_generator.py

@@ -55,6 +55,7 @@ class ModSettings:
     f4b_phantom: bool = False
     f15d_baz: bool = False
     f22_raptor: bool = False
+    f84g_thunderjet: bool = False
     f100_supersabre: bool = False
     f104_starfighter: bool = False
     f105_thunderchief: bool = False