README: Add how it works section and change cssess to CSSess

README.md

@@ -1,24 +1,29 @@
-cssess
+CSSess
 ======
 
-cssess is a JS tool that helps find extra CSS rules on your site. It is designed to be used as a bookmarklet.
+CSSess is a JS tool that helps find extra CSS rules on your site. It is designed to be used as a bookmarklet.
 
-The name cssess comes from the word secess and is pronounced the same way. secess means withdraw or retreat.
+The name CSSess comes from the word secess and is pronounced the same way. secess means withdraw or retreat.
 
-It was inspired by Helium (https://github.com/geuis/helium-css/). cssess has many improvements over Helium:
+It was inspired by Helium (https://github.com/geuis/helium-css/). CSSess has many improvements over Helium:
 
-* Helium depends on querySelectorAll, restricting use to the latest browsers. cssess uses jQuery as a selector engine.
-* Helium requires that you add URLs to check manually. cssess will spider all same domain links on the current page.
-* Helium was designed to be included within the page. cssess is designed to be used as a bookmarklet.
+* Helium depends on querySelectorAll, restricting use to the latest browsers. CSSess uses jQuery as a selector engine.
+* Helium requires that you add URLs to check manually. CSSess will spider all same domain links on the current page.
+* Helium was designed to be included within the page. CSSess is designed to be used as a bookmarklet.
 
 To install as a bookmarklet use the following in a bookmark URL:
 
-	javascript:(function(d,t){var j=d.createElement(t),s=d.getElementsByTagName(t)[0]||d.getElementsByTagName("link")[0];j.src='https://github.com/driverdan/cssess/raw/master/cssess-min.js';s.parentNode.insertBefore(j,s);})(document,"script");
+	javascript:(function(d,t){var j=d.createElement(t),s=d.getElementsByTagName(t)[0]||d.getElementsByTagName("link")[0];j.src='https://github.com/driverdan/CSSess/raw/master/CSSess-min.js';s.parentNode.insertBefore(j,s);})(document,"script");
 
-To use the un-minified version replace cssess-min.js with cssess.js.
+To use the un-minified version replace CSSess-min.js with CSSess.js.
+
+How It Works
+------------
+
+Each URL is loaded into a hidden iframe. Once the iframe has finished loading all of the stylesheets and inline styles are checked against the DOM to find unused styles.
 
 Notes
 -----
 
-* cssess will not work cross-domain due to browser security restrictions.
+* CSSess will not work cross-domain due to browser security restrictions.
 * Contributions are welcome. Feel free to fork on github and submit a pull request.