message: chore: update readme release information
  Clarify branch usage in release process
diff: @@ -38,8 +38,7 @@ The BitGoJS SDK use a number of branches to control the development of various p
  | Branch | Status | NPM | Description |
  |--------------|----------|----------|------------------------------------------------------------------------------------------------------------------------------------------------------------|
  | `master` | Unstable | N/A | Ongoing development of SDK packages |
  -| `rel/rc` | Unstable | `rc` | Deployed packages from `master` to `npm` for internal and external testing |
  -| `rel/latest` | Stable | `latest` | Deployed packages from `rel/rc` to `rel/latest`. This includes Express and is recommended to use `rel/latest` when not using Docker images for Express. |
  +| `rel/latest` | Stable | `latest` | Deployed packages from `master` to `rel/latest`. This includes Express and is recommended to use `rel/latest` when not using Docker images for Express. |
  Other tags may be released to npm (e.g. `hotfix`, `dev`, etc...), but are not considered critical to the common path for consumers usage of SDK packages unless otherwise stated.
  