[charms] Trilio Charms 21.06 release is now available

The 21.06 release of the Trilio charms are now available. Please see the Release Notes for full details: https://docs.openstack.org/charm-guide/latest/2106_Trilio.html == Highlights == * TrilioVault 4.1 HF1 The charms have added options to support new configurations presented in the TrilioVault 4.1 HF1 release. * S3 Support The charms now support using S3 storage as a backup target. == Thank you == Lots of thanks to the following people who contributed to this release via code changes, documentation updates and testing efforts. Alex Kavanagh Billy Olsen Chris MacNaughton Corey Bryant David Ames Liam Young Marian Gasparovic Peter Matulis -- OpenStack Charms Team