[build] remove unnecessary file copy

build.gradle

@@ -83,16 +83,10 @@ task docs(dependsOn: [asciidoctor, asciidoctorPdf, cleanDocs]) doLast {
         from 'build/docs/asciidocPdf/index.pdf'
         into 'docs/'
     }
-    // Copy images generated by asciidoctor-diagram to docs directory for index.html
+    // Copy images to docs directory for index.html
     copy {
         from 'build/docs/asciidoc/'
         include 'Chapter*/images/*'
         into 'docs'
     }
-    // Copy images created by the user to the docs directory for index.html
-    copy {
-        from 'src/docs/asciidoc/'
-        include 'Chapter*/images/*'
-        into 'docs'
-    }
 }