fix a typo in stable plugin documentation (#101812)

docs/plugins/development/creating-stable-plugins.asciidoc

@@ -59,7 +59,7 @@ for the plugin. If you need other resources, package them into a resources JAR.
 [discrete]
 ==== Development process
 
-Elastic provides a Grade plugin, `elasticsearch.stable-esplugin`, that makes it
+Elastic provides a Gradle plugin, `elasticsearch.stable-esplugin`, that makes it
 easier to develop and package stable plugins. The steps in this section assume
 you use this plugin. However, you don't need Gradle to create plugins.
 
@@ -128,4 +128,4 @@ extend `ESClientYamlSuiteTestCase`.
 [[plugin-descriptor-file-stable]]
 ==== The plugin descriptor file for stable plugins
 
-include::plugin-descriptor-file.asciidoc[]
+include::plugin-descriptor-file.asciidoc[]