feat(mindustry): Increased unit formation slot limit for supporters (xpdustry#405)

Suggested in #admin-chat.

Author: JamesBunny404

imperium-mindustry/src/main/kotlin/com/xpdustry/imperium/mindustry/formation/FormationListener.kt

@@ -161,6 +161,7 @@ class FormationListener(instances: InstanceManager) : ImperiumApplication.Listen
         if (account != null) {
             slots =
                 when {
+                    accounts.selectAchievement(account.id, Achievement.SUPPORTER) -> 18
                     accounts.selectAchievement(account.id, Achievement.HYPER) -> 18
                     accounts.selectAchievement(account.id, Achievement.ACTIVE) -> 12
                     account.rank >= Rank.VERIFIED -> 8