Add Can destroy Account Outputs tx cap flag rule

tips/TIP-0042/tip-0042.md

@@ -845,6 +845,9 @@ A transaction that transitions an account is only valid if all of the following
 - Newly created foundries in the transaction that map to different accounts can be interleaved when it comes to sorting.
 - When a consumed account output has _Features_ defined in `Immutable Features` and a corresponding account output on
   the output side, `Immutable Features` is not allowed to change.
+- If there is no corresponding Account Output with the same _Account ID_ on the output side, the Account is being
+  destroyed. The transaction is invalid if an Account Output is burned and the _Can destroy Account Outputs_ flag in the
+  _Transaction Capabilities_ is **unset**.
 
 ### Created Outputs