docs/rofl/remove: Mention master key will be lost forever

Author: matevz

docs/rofl.md

@@ -336,12 +336,17 @@ Run `rofl remove` to deregister your ROFL app:
 The deposit required to register the ROFL app will be returned to the current
 administrator account.
 
-:::danger Secrets will be permanently lost
+:::danger Secrets and derived keys will be permanently lost
 
 All secrets stored on-chain will be permanently lost when the ROFL app is
 deregistered! If you backed up your manifest file, those secrets will also be
 unretrievable since they were encrypted with a ROFL deployment-specific keypair.
 
+Similarly, the ROFL's master secret for [key generation] will be lost, so you
+will not be able to generate the same keys in the future.
+
+[derived keys]: https://github.com/oasisprotocol/oasis-sdk/blob/main/docs/rofl/features/appd.md#key-generation
+
 :::
 
 ### ROFL provider tooling {#provider}