grails readme (#7365)

plugins/grails/README.md

 # Grails plugin
 
-Adds tab-completion of [Grails](https://grails.org/) script names to the command line use of grails.
+This plugin adds completion for the [Grails 2 CLI](https://grails.github.io/grails2-doc/2.5.x/guide/commandLine.html)
 
 To use it, add `grails` to the plugins array in your zshrc file:
 
@@ -14,3 +14,58 @@ It looks for scripts in the following paths:
 - `~/.grails/scripts`
 - `./scripts`
 - `./plugins/*/scripts`
+
+## Grails Commands
+- `add-proxy`
+- `alias`
+- `bootstrap`
+- `bug-report`
+- `clean`
+- `clean-all`
+- `clear-proxy`
+- `compile`
+- `console`
+- `create-app`
+- `create-controller`
+- `create-domain-class`
+- `create-filters`
+- `create-integration-test`
+- `create-multi-project-build`
+- `create-plugin`
+- `create-pom`
+- `create-script`
+- `create-service`
+- `create-tag-lib`
+- `create-unit-test`
+- `dependency-report`
+- `doc`
+- `help`
+- `init`
+- `install-app-templates`
+- `install-dependency`
+- `install-plugin`
+- `install-templates`
+- `integrate-with`
+- `interactive`
+- `list-plugin-updates`
+- `list-plugins`
+- `migrate-docs`
+- `package`
+- `package-plugin`
+- `plugin-info`
+- `refresh-dependencies`
+- `remove-proxy`
+- `run-app`
+- `run-script`
+- `run-war`
+- `set-grails-version`
+- `set-proxy`
+- `set-version`
+- `shell`
+- `stats`
+- `stop-app`
+- `test-app`
+- `uninstall-plugin`
+- `url-mappings-report`
+- `war`
+- `wrapper`