Merge pull request #281 from /issues/281/davidji99-create-releasemd-doc

Create RELEASE.md doc

RELEASE.md

@@ -0,0 +1,31 @@
+## Release Flow
+
+Since the migration to the [Terraform registry](https://registry.terraform.io/), this repository's maintainers now have
+the ability to self-publish Terraform Heroku provider releases. This process leverages Github Actions
+and [`goreleaser`](https://github.com/goreleaser/goreleaser) to build, sign, and upload provider binaries to a Github release.
+
+The release flow is as follows:
+1. Create a [new Github release](https://github.com/heroku/terraform-provider-heroku/releases/new).
+    - For the 'Tag version' and 'Release title' fields, please enter a new & valid semantic version such as `v1.2.3`.
+    - For the 'Describe this release' field, please follow the following format:
+    ```markdown
+    ## FEATURES:
+    - Some text that describes the pull request (#123)
+
+    ## IMPROVEMENTS:
+    ...
+
+    ## BUG FIXES:
+    ...
+    ```
+1. Click 'Publish release' button.
+    - Note: Draft releases will not trigger the release workflow or show up in the Terraform registry.
+1. Github Actions will trigger the release workflow which can be
+[viewed here](https://github.com/heroku/terraform-provider-heroku/actions?query=workflow%3Arelease).
+After the workflow executes successfully, the Github release created in the prior step will
+have the relevant assets available for consumption.
+1. The new release will show up in https://registry.terraform.io/providers/heroku/heroku/latest for consumption
+by terraform `0.13.X` users.
+1. For terraform `0.12.X` users, the new release is available for consumption once it is present in
+https://releases.hashicorp.com/terraform-provider-heroku/.
+