Mention dependency name for docker image tags

content/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file.md

@@ -175,7 +175,9 @@ updates:
 
 Use the `allow` option to customize which dependencies are updated. This applies to both version and security updates. You can use the following options:
 
-- `dependency-name`—use to allow updates for dependencies with matching names, optionally using `*` to match zero or more characters. For Java dependencies, the format of the `dependency-name` attribute is: `groupId:artifactId`, for example: `org.kohsuke:github-api`.
+- `dependency-name`—use to allow updates for dependencies with matching names, optionally using `*` to match zero or more characters. 
+     - For Java dependencies, the format of the `dependency-name` attribute is: `groupId:artifactId`; for example: `org.kohsuke:github-api`. 
+     - For Docker image tags, the format is the full name of the repository; for example, for an image tag of `<account ID>.dkr.ecr.us-west-2.amazonaws.com/base/foo/bar/ruby:3.1.0-focal-jemalloc`, use `base/foo/bar/ruby`.
 - `dependency-type`—use to allow updates for dependencies of specific types.
 
   | Dependency types | Supported by package managers | Allow updates |