Fix textual error in docs for base plugin (PR asciidoctor#724)

Correcting a minor textual error

docs/modules/ROOT/pages/asciidoctorj-base-plugin.adoc

@@ -114,7 +114,7 @@ Please refer to xref:asciidoc:attributes:assignment-precedence.adoc#altering-the
 [[asciidoctorj-modules,{asciidoctorj-name} Modules]]
 == Versions of modules
 
-The modules block currently supports four elements
+The modules block currently supports five elements:
 
 [source,groovy]
 .build.gradle
@@ -145,7 +145,7 @@ asciidoctorj {
 <4> Version of https://github.com/asciidoctor/asciidoctorj-groovy-dsl[Groovy Extensions DSL]. If not specified and no extensions are specified, Groovy DSL will not be used. However, if any extensions are added without setting an explicit version and default version will be used.
 <5> https://github.com/asciidoctor/asciidoctor-leanpub-converter[Asciidoctor Leanpub Converter] version. If not specified asciidoctorj-leanpub will not be on the classpath. If you plan to use the Leanpub backend and not using the Leanpub plugin, then you need to set a version here.
 
-When using the Kotlin DSL the same settings can be achieved use something similar `getModules().getPdf().version("1.2.3")`.
+When using the Kotlin DSL the same settings can be achieved use something similar: `getModules().getPdf().version("1.2.3")`.
 In a similar fashion shortcuts can be achieved in the Groovy DSL:
 
 [source,groovy,role="primary"]