bm: add "Void Machines" civic, machine version of "Void Hive"

better_mi/common/governments/civics/~01_bm_civics.txt

@@ -0,0 +1,20 @@
+civic_bm_void_machines = {
+	playable = { has_lithoids = yes }
+	ai_playable = { has_lithoids = yes }
+	description = civic_tooltip_void_hive_effects
+	potential = {
+		authority = { value = auth_machine_intelligence }
+	}
+	random_weight = {
+		base = @civic_default_random_weight
+	}
+	ai_weight = {
+		base = @ai_civic_default_base_weight
+	}
+
+	modifier = {
+		megastructures_cost_mult = -0.05
+		megastructure_build_speed_mult = 0.1
+		councilor_gestalt_growth_exp_gain = @gestalt_civic_node_xp_rate
+	}
+}