2021.05-rc1 Public Release

This release was produced using the Debian 9 based
ONIE Docker build container configuration generated
using Dedicated User Environment (DUE) version 2.3.0

Instructions and source for replicating this ONIE build
environment are available at:
https://github.com/CumulusNetworks/DUE

New Hardware Platforms
======================
 Inventec D7332
 Silicom Madrid

Build and Release / Improvements
================================
 CONTRIBUTING.md updated patch style guide.
 Updated build information in onie-build-targets.json

Bug Fixes / Improvements
=========================
 Delta tx4810, tn48m - added newlines to a few patches.
   The patches applied correctly in DUE containers, but
   did not in a different environment. (PR #950)
 Delta tx4810 - disable unused ethernet interfaces

Misc:
=====
NONE