Document where headerbytes and publickey come from

src/chatmodel.cpp

@@ -385,8 +385,9 @@ QString MainWindow::createHeaderMemo(QString type, QString cid, QString zaddr, Q
     h["z"]   = zaddr;           // string, zaddr to respond to
     h["cid"] = cid;             // string, conversation id (UUID)
     h["t"]   = type;            // string, Memo or incoming contact request
-    h["e"]   = headerbytes;     // string, hex-encoded libsodium headerbytes
-    h["p"]   = publickey;       // string, hex-encoded libsodium public key
+    h["e"]   = headerbytes;     // string, hex-encoded libsodium headerbytes from crypto_secretstream_xchacha20poly1305_init_push()
+    h["p"]   = publickey;       // string, hex-encoded libsodium public key from crypto_kx_seed_keypair()
+
 
     j.setObject(h);
     header = j.toJson();