Add link to open pull request

Author: tbcrawford

CHANGES.md

@@ -12,7 +12,7 @@ We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (
 ## [Unreleased]
 ### Added
 * New static method to `DiffMessageFormatter` which allows to retrieve diffs with their line numbers ([#1960](https://github.com/diffplug/spotless/issues/1960))
-* Gradle support for shell via [shfmt](https://github.com/mvdan/sh).
+* Gradle support for shell via [shfmt](https://github.com/mvdan/sh). ([#1994](https://github.com/diffplug/spotless/pull/1994))
 ### Changes
 * Use palantir-java-format 2.39.0 on Java 21. ([#1948](https://github.com/diffplug/spotless/pull/1948))