[asciidoc-lang-dev] Trivial docco fix

[Ian Darwin <ian@xxxxxxxxxxxxx>]

Suggested git commit -m "Add missing verb and reword slightly, from 
idarwin1fe"

asciidoc-lang $ git diff
diff --git a/asg/README.adoc b/asg/README.adoc
index 80824b4..b8e3b28 100644
--- a/asg/README.adoc
+++ b/asg/README.adoc
@@ -23,7 +23,7 @@ To run the self test suite, invoke the npm `test` task:

 == Validate output files

-The TCK asserts that the ASG that an implementation produces the 
expected ASG for a given AsciiDoc input document.
+The TCK asserts that an implementation produces an ASG which matches 
the expected ASG for a given AsciiDoc input document.
 You can validate those expected output files using the npm `validate` 
task:

  $ npm run validate --dir=/path/to/tests