Fix #205: Document branching policy (#461)

Author: samdark

src/internals/020-package-release.md

@@ -12,20 +12,30 @@
 - phpdoc is alright.
 - Public API is alright.
 
+## Release branch policy
+
+Use `master` for all regular releases.
+
+Create a separate branch only when releasing a new version for a previous major version. In this case, create the
+branch from the latest tag in that previous major version line and apply only the changes needed for the release.
+
 ## Release instruction
 
 Release a package via [Yii Development Tool](005-development-tool.md). 
 
 1. Check that you can sign commits locally (see 
 [Signing commits](https://docs.github.com/en/authentication/managing-commit-signature-verification/signing-commits)).
 
-2. Pull last changes from the `master` branch:
+2. For regular releases, pull last changes from the `master` branch:
 
 ```shell
 ./yii-dev git/checkout master package-name
 ./yii-dev git/pull package-name
 ```
 
+For previous major version releases, use the branch created according to the release branch policy instead of
+`master`.
+
 3. Check the package for compliance with the criteria above.
 
 4. Run `release/make` command:
@@ -34,7 +44,7 @@ Release a package via [Yii Development Tool](005-development-tool.md).
 ./yii-dev release/make package-name
 ```
 
-5. Select the version type (major, minor or path).
+5. Select the version type (major, minor or patch).
 
 6. On the question "Push commits and tags, and release on GitHub?" check a diff. If the diff is alright, answer "yes."