Update RELEASE.md and rename migration included in v1.3.0 release (#5250

)

## Motivation
Add additional info to RELEASE.md and rename the DB migration included in `v1.3.0` release series.

## Test Plan
n/a

## TODO
<!-- This section should be removed when all items are complete -->
- [x] Explain motivation or link existing issue(s)
- [x] Test changes and document test plan
- [x] Update documentation as needed
- [x] Update [changelog](../CHANGELOG.md) as needed

RELEASE.md

@@ -2,9 +2,9 @@
 
 ## Releasing a major version
 
-Rename UNRELEASED to a concrete `version` and create a PR with commit: Release `version`.
-Branch name should match the `version` set in CHANGELOG.
-Additionally tag that same commit with 0 as a patch version (if branch is v1.1 - tag is v1.1.0).
+Update `CHANGELOG.md` by renaming UNRELEASED to a concrete version `x.y.0` and create a PR with commit: Release `x.y.0`.
+Branch name should match the version set in CHANGELOG but only include major and minor version: `vx.y` (e.g. v1.1).
+Additionally tag that same commit with `0` as a patch version (if branch is v1.1 - tag is v1.1.0).
 
 ## Releasing a minor version
 
@@ -39,3 +39,9 @@ After releasing a new major or minor version, create a new UNRELEASED section at
 
 ### Improvements
 ```
+
+Additionally if a `dddd_next.sql` exists in `sql/migrations/state` and/or `sql/migrations/local` rename it to
+`dddd_vx.y.z.sql` where `x.y.z` is the new version and `dddd` is the next available number.
+
+The first PR that needs a DB migrations creates a new `dddd_next.sql` file in `sql/migrations/state` and/or
+`sql/migrations/local`.