Added some comments to JS files

background.js

+/*	Enables the page action (i.e., the browser toolbar icon).
+	*/
 chrome.runtime.onInstalled.addListener(() => {
 	chrome.declarativeContent.onPageChanged.removeRules(undefined, () => {
 		chrome.declarativeContent.onPageChanged.addRules([{
 	});
 });
 
+/*	Toggle the toolbar icon based on whether stickies are, or are not, set to
+	be killed on the current tab.
+
+	This listener receives a message from the content script (contentScript.js);
+	the content script actually determines what the settings for the current
+	tab are.
+	*/
 chrome.runtime.onMessage.addListener((request, sender, sendResponse) => {
 	let icons = request.killingStickies ? {
 			"16":	"images/ASK_on_16.png",

contentScript.js

 /* HELPERS */
 /***********/
 
+/*	Given the result of a query to storage (for the matching and exclusion 
+	pattern lists, and the current mode - whitelist or blacklist), this function
+	determines whether stickies should be killed on the currently loaded page.
+
+	Stickies are killed if the following is true:
+	
+	(blacklist mode is active, AND 
+	 at least one matching pattern matches the URL of the current page, AND
+	 zero exclusion patterns match the URL of the current page)
+		 OR 
+	 (whitelist mode is active, AND
+	  zero exclusion matters match the URL of the current page)
+	*/
 function checkForShouldKillSticky(result) {
 	var shouldKillSticky = false;
-	
+
+	/*	If whitelist mode is active, then the matching patterns list is treated
+		as containing a single pattern which will match all possible URLs.
+		Patterns that are empty strings (i.e., blank lines in the patterns 
+		lists) are ignored, as are any patterns that begin with a pound sign (#)
+		(this allows for comments in the patterns lists). */
 	let matchingPatterns = result.mode == "whitelist" ?
 						   [ ".*" ] :
 						   (typeof result.matchingPatterns != "undefined" ?
 	return shouldKillSticky;
 }
 
+/*	This function sends a message to the background script (background.js), 
+	which then updates the page action icon (i.e., the browser toolbar icon)
+	to reflect whether killing stickies is enabled on the current page.
+	*/
 function updateIcon(shouldKillSticky) {
 	chrome.runtime.sendMessage({ "killingStickies" : shouldKillSticky });
 }

functions.js

 /* HELPERS */
 /***********/
 
+/*	This is the code that actually does the sticky killing! It simply selects
+	all elements whose 'position' CSS property has a computed value of either
+	'sticky' or 'fixed', and removes those elements.
+	*/
 function killSticky() {
 	console.log("Killing all stickies!");
 	document.querySelectorAll('body *').forEach(element => {