Update README.md - fix open branches

README.md

@@ -17,8 +17,9 @@ Branch                                                            | Purpose
 ------------------------------------------------------------------| ---------------------------- | ---------------------------------------
 [21.0](https://gitlab.cern.ch/atlas/athena/tree/21.0)             | Tier0 and MC16c              | Athena, 21.0.X
 [21.0-mc16a](https://gitlab.cern.ch/atlas/athena/tree/21.0-mc16a) | MC16a bugfixes               | Athena, 21.0.20.Y
+[21.0-mc16d](https://gitlab.cern.ch/atlas/athena/tree/21.0-mc16d) | MC16d bugfixes               | Athena, 21.0.20.Y
+[21.0-TrigMC](https://gitlab.cern.ch/atlas/athena/tree/21.0-TrigMC)  | MC production with new trigger developments | AthenaP1, No production releases
 [21.1](https://gitlab.cern.ch/atlas/athena/tree/21.1)             | HLT and P1 monitoring        | AthenaP1, 21.1.X
-[21.1-dev](https://gitlab.cern.ch/atlas/athena/tree/21.1-dev)     | HLT and P1 Run 2 Developments | AthenaP1, No production releases
 [21.2](https://gitlab.cern.ch/atlas/athena/tree/21.2)             | Derivations and Analysis     | AthDerivations + (Ath)AnalysisBase, 21.2.X
 [21.3](https://gitlab.cern.ch/atlas/athena/tree/21.3)             | MC18 Simulation              | Athena + AthSimulation, 21.3.X
 [21.6](https://gitlab.cern.ch/atlas/athena/tree/21.6)             | Event Generation             | AthGenerators, 21.6.X