tweak comments

index.html

@@ -17,10 +17,10 @@
 		<link rel="stylesheet" href="css/reveal.css">
 		<link rel="stylesheet" href="css/theme/black.css" id="theme">
 
-		<!-- For syntax highlighting -->
+		<!-- Code syntax highlighting -->
 		<link rel="stylesheet" href="lib/css/zenburn.css">
 
-		<!-- Include the appropriate print stylesheet -->
+		<!-- Printing and PDF exports -->
 		<script>
 			var link = document.createElement( 'link' );
 			link.rel = 'stylesheet';
@@ -390,7 +390,7 @@ Reveal.addEventListener( 'customevent', function() {
 
 		<script>
 
-			// Full list of configuration options available here:
+			// Full list of configuration options available at:
 			// https://github.com/hakimel/reveal.js#configuration
 			Reveal.initialize({
 				controls: true,
@@ -400,7 +400,7 @@ Reveal.addEventListener( 'customevent', function() {
 
 				transition: 'slide', // none/fade/slide/convex/concave/zoom
 
-				// Optional libraries used to extend on reveal.js
+				// Optional reveal.js plugins
 				dependencies: [
 					{ src: 'lib/js/classList.js', condition: function() { return !document.body.classList; } },
 					{ src: 'plugin/markdown/marked.js', condition: function() { return !!document.querySelector( '[data-markdown]' ); } },