Add docs

src/spectator/runner.cr

@@ -1,25 +1,38 @@
 module Spectator
   # Main driver for executing tests and feeding results to formatters.
   class Runner
+    # Creates the test suite runner.
+    # Specify the test `suite` to run and any additonal configuration.
     def initialize(@suite : TestSuite, @config : Config)
     end
 
+    # Runs the test suite.
+    # This will run the selected examples
+    # and invoke the formatter to output results.
     def run : Nil
-      results = [] of Result
+      # Indicate the suite is starting.
       @config.formatter.start_suite
+
+      # Run all examples and capture the results.
+      results = [] of Result
       elapsed = Time.measure do
         results = @suite.map do |example|
           run_example(example).as(Result)
         end
       end
-      @config.formatter.end_suite(Report.new(results, elapsed))
+
+      # Generate a report and pass it along to the formatter.
+      report = Report.new(results, elapsed)
+      @config.formatter.end_suite(report)
     end
 
+    # Runs a single example and returns the result.
+    # The formatter is given the example and result information.
     private def run_example(example) : Result
       @config.formatter.start_example(example)
-      result = Internals::Harness.run(example)
+      Internals::Harness.run(example).tap do |result|
         @config.formatter.end_example(result)
-      result
+      end
     end
   end
 end