Add RELEASE doc. (#1433)

Signed-off-by: Phillip Hoff <[email protected]>

Author: philliphoff

docs/RELEASE.md

@@ -0,0 +1,69 @@
+# Dapr .NET SDK Release Process
+
+> This information is intended for SDK maintainers. SDK users can ignore this document.
+
+## Publish a SDK Release Candidate (RC)
+
+RC release versions canonically use the form `<version>-rc<iteration>` where `<version>` represents the overall release version (e.g. `1.0`) and `<iteration>` represents a specific iteration of RC release (e.g. `01`, `02`, ..., `0n`). 
+
+Assume we intend to release `<version>` (e.g. `1.0-rc01`) of the SDK.
+
+1. Create a release branch (if not already done) from `master`
+
+   ```bash
+   git checkout -b release-<version>
+   ```
+
+1. Push the release branch to the `dotnet-sdk` repo (i.e. typically `origin`)
+
+   ```bash
+   git push origin v<version>
+   ```
+
+1. Create a tag on the release branch for the RC version
+
+   ```bash
+   git tag v<version>-rc<iteration>
+   ```
+
+1. Push the tag to the `dotnet-sdk` repo (i.e. typically `origin`)
+
+   ```bash
+   git push origin v<version>-rc<iteration>
+   ```
+
+   > This final step will generate a build and automatically publish the resulting packages to NuGet.
+
+## Publish a SDK Release
+
+Official (i.e. supported) release versions canonically use the form `<version>` where `<version>` represents the overall release version (e.g. `1.0`). 
+
+1. Create a release branch (if not already done) from `master`
+
+   ```bash
+   git checkout -b release-<version>
+   ```
+
+1. Push the release branch to the `dotnet-sdk` repo (i.e. typically `origin`)
+
+   ```bash
+   git push origin v<version>
+   ```
+
+1. Create a tag on the release branch for the release
+
+   ```bash
+   git tag v<version>
+   ```
+
+1. Push the tag to the `dotnet-sdk` repo (i.e. typically `origin`)
+
+   ```bash
+   git push origin v<version>
+   ```
+
+   > This final step will generate a build and automatically publish the resulting packages to NuGet.
+
+## NuGet Package Publishing
+
+Publishing to NuGet requires keys generated by a member of the Dapr organization. Such keys are added as a [GitHub Action secret](https://github.com/dapr/dotnet-sdk/settings/secrets/actions) with the name `NUGETORG_DAPR_API_KEY` These keys expire and therefore must be maintained and the GitHub Actions secret updated periodically.