Update release instructions (#1778)

Author: trask

RELEASING.md

@@ -1,4 +1,6 @@
-# Making a Release
+# Releasing
+
+## Preparing a new release
 
 - Close the [release milestone](https://github.com/open-telemetry/semantic-conventions/milestones)
   if there is one.
@@ -7,17 +9,13 @@
   if needed.
 - Run [opentelemetry.io workflow](https://github.com/open-telemetry/opentelemetry.io/actions/workflows/build-dev.yml)
   against `semantic-conventions` submodule as a smoke-test for docs. Fix broken links, if any.
-- Create a staging branch for the release.
-  - Update `schema-next.yaml` file and move to `schemas/{version}`
-    - Ensure the `next` version is appropriately configured as the `{version}`.
-    - Copy `schema-next.yaml` to `schemas/{version}`.
-    - Add `next` as a version in `schema-next.yaml` version.
-  - Run `make chlog-update VERSION=v{version}`
-    - `make chlog-update` will clean up all the current `.yaml` files inside the
-      `.chloggen` folder automatically
-    - Double check that `CHANGELOG.md` is updated with the proper `v{version}`
-  - Send staging branch as PR for review.
-- After the release PR is merged, create a [new release](https://github.com/open-telemetry/semantic-conventions/releases/new):
+- Run the [prepare release workflow](https://github.com/open-telemetry/semantic-conventions/actions/workflows/prepare-release.yml).
+  - Review and merge the pull request that it creates.
+  - Note: the PR will need to be closed and the workflow re-run if any non-chore PRs are merged to `main` while the PR is open.
+
+## Making the release
+
+- Create a [new release](https://github.com/open-telemetry/semantic-conventions/releases/new):
   - Set title and tag to `v{version}`
   - Set target to the commit of the merged release PR
   - Copy changelog to the release notes