gradle: add README (#7211)

plugins/gradle/README.md

@@ -0,0 +1,23 @@
+## Gradle Plugin
+
+This plugin adds completions and aliases for [Gradle](https://gradle.org/).
+
+To use it, add `gradle` to the plugins array in your zshrc file:
+
+```zsh
+plugins=(... gradle)
+```
+
+## Usage
+
+This plugin creates an alias `gradle` which is used to determine whether the current working directory has a gradlew file. If gradlew is present it will be used otherwise `gradle` is used directly. Gradle tasks can be executed directly without regard for whether it is `gradle` or `gradlew`
+
+Examples:
+```zsh
+gradle test
+gradle build
+```
+
+## Completion
+
+The completion provided for this plugin caches the parsed tasks into a file named `.gradletasknamecache` in the current working directory, so you might want to add that to your `.gitignore` file so that it's not accidentally committed.