README: add release management

Author: Bryan Latten

README.md

@@ -215,5 +215,26 @@ This will:
 - Validates a large file upload
 - Boots container with specific NewRelic configuration overrides
 
-The test matrix is run automatically per pull request on Travis CI.
+### Release Management
 
+Github actions provide the machinery for testing (ci.yaml) and producing tags distributed through Docker Hub (publish.yaml). Testing will confirm that `nginx` is able to serve content in various configurations, but also that it can terminate TLS with self-signed certificates. Once a tested and approved PR is merged, simply cutting a new semantically-versioned tag will generate the a matrix of tagged builds. See Container tag scheme above.
+
+Platform support is available for multiple architectures:
+- `linux/amd64`: Ubuntu and Alpine variants
+- `linux/arm64`: Ubuntu variants-only
+
+To add new variant based on a new Dockerfile, add an entry to `matrix.props` within `./github/workflows` YAML files.
+
+### Github Actions: Simulation
+
+docker-nginx uses Github Actions for CI/CD. Simulated workflows can be achieved locally with `act`. All commands must be executes from repository root.
+
+Pre-reqs: tested on Mac
+1. [Docker Desktop](https://www.docker.com/products/docker-desktop)
+1. [act](https://github.com/nektos/act)
+
+Pull request simulation: executes successfully, but only on ARM devices (ex. Apple M1). ARM emulation through QEMU on X64 machines does not implement the full kernel functionality required by nginx at this time.
+- `act pull_request`
+
+Publish simulation: executes, but fails (intentionally) without credentials
+- `act`