added underage rule

src/Rules/Underage.md

@@ -0,0 +1,13 @@
+# Underage
+Communicating that you're under 18, when deemed as sincere, regardless what your actual age is, is prohibited.
+
+Your actual age is not relevant, since:
+- If we have reason to believe you are under 18, we may encounter legal liabilities allowing you to remain in the server.
+- If you are actually over 18, and sincerely say you are under 18, we would consider that age-fetish activity and would ban you on those grounds.
+
+*"Communicating" in this context may include instances where officials have a strong suspicion that you are under 18, even if you do not state it directly.*
+
+*Banning you for admitting that you're under 18 (when you actually are) should not be interpreted as a reprimand, but it is the only safe and responsible way to ensure you can't access the server whilst ensuring that no record of your under-18 status is kept.*
+
+⚠️ **External**: May apply to activity outside of Cabal.  
+⚠️ **Terminal**: Violators are subject to reprimand without warning.