Add town growth setting, rate depends on proportion of transported cargo

src/table/settings.ini

@@ -1751,6 +1751,20 @@ strhelp  = STR_CONFIG_SETTING_TOWN_GROWTH_HELPTEXT
 strval   = STR_CONFIG_SETTING_TOWN_GROWTH_EXTREME_SLOW
 orderproc = OrderTownGrowthRate
 
+[SDT_VAR]
+base     = GameSettings
+var      = economy.town_growth_cargo_transported
+type     = SLE_UINT8
+def      = 0
+min      = 0
+max      = 100
+interval = 10
+str      = STR_CONFIG_SETTING_TOWN_GROWTH_CARGO_TRANSPORTED
+strhelp  = STR_CONFIG_SETTING_TOWN_GROWTH_CARGO_TRANSPORTED_HELPTEXT
+strval   = STR_CONFIG_SETTING_PERCENTAGE
+cat      = SC_EXPERT
+patxname = ""town_growth.economy.town_growth_cargo_transported""
+
 [SDT_VAR]
 base     = GameSettings
 var      = economy.larger_towns