Add documentation about technology tree file format

Author: MahBoiDeveloper

docs/TechTreeJson.md

@@ -0,0 +1,76 @@
+# Tech Tree File Format
+
+The tech tree for Generals Zero Hour is built from the information in the `TechTree.json` file, rather than from the game`s ini files, due to the simplification of information retrieval and data loading.
+
+The tech tree description file is a JSON structure containing a list of factions called `TechTree`, each of which consists of the following fields: `ShortName`, `DisplayName`, `DisplayNameDescription`, and the following lists: `Buildings`, `Infantry`, `Vehicles`, `Aircraft`. Each element in these lists is also a structure with fields `Name` (defines which .webp file should be loaded from the `Resources\Icons` directory), `IngameName` (defines which string from the .csf file should be taken as the object name) and a list of lists `KeyboardLayouts`. These layouts represent the possible combinations of the GUI for a unit or building. Each element in a layout is a structure with two fields: `IconName` (which defines which .webp file should be loaded from the `Resources/Icons` directory) and `HotkeyString` (which defines which string from the .csf file should be used for the hotkey of the action).
+
+Example:
+
+```json
+{
+    "TechTree" : 
+    [
+        {
+            "ShortName"               : "USA",
+            "DisplayName"             : "USA",
+            "DisplayNameDescription"  : "United Stated Of America",
+
+            "Buildings" : 
+            [
+                {
+                    "Name"            : "USAColdFusionReactor",
+                    "IngameName"      : "OBJECT:ColdFusionReactor",
+                    "KeyboardLayouts" : 
+                    [
+                        [
+                            {"IconName" : "USAControlRods", "HotkeyString" : "CONTROLBAR:UpgradeAmericaAdvancedControlRods"},
+                        ]
+                    ]
+                }
+            ],
+
+            "Infantry" : 
+            [
+                {
+                    "Name"            : "USARanger",
+                    "IngameName"      : "OBJECT:Ranger",
+                    "KeyboardLayouts" : 
+                    [
+                        [
+                            {"IconName" : "USAFlashbangs",       "HotkeyString" : "CONTROLBAR:FlashBangGrenadeMode"},
+                        ]
+                    ]
+                }
+            ],
+
+            "Vehicles" : 
+            [
+                {
+                    "Name"            : "USADozer",
+                    "IngameName"      : "OBJECT:Dozer",
+                    "KeyboardLayouts" : 
+                    [
+                        [
+                            {"IconName" : "USAColdFusionReactor",    "HotkeyString" : "CONTROLBAR:ConstructAmericaPowerPlant"},
+                        ]
+                    ]
+                }
+            ],
+
+            "Aircrafts" : 
+            [
+                {
+                    "Name"            : "USAChinook",
+                    "IngameName"      : "OBJECT:Chinook",
+                    "KeyboardLayouts" : 
+                    [
+                        [
+                            {"IconName" : "USACombatDrop", "HotkeyString" : "CONTROLBAR:CombatDrop"},
+                        ]
+                    ]
+                }
+            ],
+        }
+    ]
+}
+```