Polish "Document how to use org.asciidoctor.jvm.convert Gradle plugin"

See gh-744

docs/src/docs/asciidoc/getting-started.adoc

@@ -150,43 +150,44 @@ macro.
 	}
 
 	configurations {
-		asciidoctorExt
+		asciidoctorExt <2>
 	}
 
 	dependencies {
-		asciidoctorExt 'org.springframework.restdocs:spring-restdocs-asciidoctor:{project-version}' <2>
-		testImplementation 'org.springframework.restdocs:spring-restdocs-mockmvc:{project-version}' <3>
+		asciidoctorExt 'org.springframework.restdocs:spring-restdocs-asciidoctor:{project-version}' <3>
+		testImplementation 'org.springframework.restdocs:spring-restdocs-mockmvc:{project-version}' <4>
 	}
 
-	ext { <4>
+	ext { <5>
 		snippetsDir = file('build/generated-snippets')
 	}
 
-	test { <5>
+	test { <6>
 		outputs.dir snippetsDir
 	}
 
-	asciidoctor { <6>
-        inputs.dir snippetsDir <7>
-        configurations 'asciidoctorExt' <8>
-		dependsOn test <9>
+	asciidoctor { <7>
+		inputs.dir snippetsDir <8>
+		configurations 'asciidoctorExt' <9>
+		dependsOn test <10>
 	}
 ----
 <1> Apply the Asciidoctor plugin.
-<2> Add a dependency on `spring-restdocs-asciidoctor` in the `asciidoctorExt`
+<2> Declare the `asciidoctorExt` configuration for dependencies that extend Asciidoctor.
+<3> Add a dependency on `spring-restdocs-asciidoctor` in the `asciidoctorExt`
 configuration. This will automatically configure the `snippets` attribute for use in your
 `.adoc` files to point to `build/generated-snippets`. It will also allow you to use the
 `operation` block macro.
-<3> Add a dependency on `spring-restdocs-mockmvc` in the `testImplementation`
+<4> Add a dependency on `spring-restdocs-mockmvc` in the `testImplementation`
 configuration. If you want to use `WebTestClient` or REST Assured rather than MockMvc,
 add a dependency on `spring-restdocs-webtestclient` or `spring-restdocs-restassured`
 respectively instead.
-<4> Configure a property to define the output location for generated snippets.
-<5> Configure the `test` task to add the snippets directory as an output.
-<6> Configure the `asciidoctor` task.
-<7> Configure the snippets directory as an input.
-<8> Add the configuration for the Asciidoctor external library extensions.
-<9> Make the task depend on the test task so that the tests are run before the
+<5> Configure a property to define the output location for generated snippets.
+<6> Configure the `test` task to add the snippets directory as an output.
+<7> Configure the `asciidoctor` task.
+<8> Configure the snippets directory as an input.
+<9> Configure the use of the `asciidoctorExt` configuration for extensions.
+<10> Make the task depend on the test task so that the tests are run before the
 documentation is created.
 ====