Only output plugin comments if there's content to display

Also, more readme improvements

eth-escape-headspace.php

@@ -152,9 +152,6 @@ class ETH_Escape_HeadSpace2 {
 			return;
 		}
 
-		// Build output
-		echo "\n<!-- Escape HeadSpace2 by Erick Hitter; ethitter.com -->\n";
-
 		// Handle basic, string-containing keys
 		$output = array();
 
@@ -209,11 +206,8 @@ class ETH_Escape_HeadSpace2 {
 
 		// Output whatever we've built
 		if ( ! empty( $output ) ) {
-			echo implode( "\n", $output );
+			echo "\n<!-- Escape HeadSpace2 by Erick Hitter; https://eth.pw/escape-hs2 -->\n" . implode( "\n", $output ) . "\n<!-- Escape HeadSpace2 -->\n";
 		}
-
-		// Mark end of output
-		echo "\n<!-- Escape HeadSpace2 -->\n";
 	}
 
 	/**

readme.txt

@@ -14,7 +14,11 @@ Output existing HeadSpace2 data without the original plugin. Deactivate HeadSpac
 
 Outputs data stored in HeadSpace2 post meta without requiring HeadSpace2. This allows one to remove the now-unmaintained HeadSpace2 plugin without losing the data associated with legacy content.
 
-Note that many current SEO plugins for WordPress also handle migration, but since I don't use any such plugins on my network, I created this alternative.
+The HeadSpace2 plugin is no longer maintained and generates many warnings when used with PHP 7. With this in mind, and without judging the original plugin, I created this option to preserve the plugin's output for SEO purposes. The plugin *does not* allow HeadSpace2 data to be edited; it only allows search engines to continue accessing it.
+
+Note that many current SEO plugins also handle migration from HeadSpace2, but since I don't use any such plugins on my network, I created this alternative.
+
+For a full list of the HeadSpace2 data that's supported, see the FAQ.
 
 == Installation ==
 
@@ -27,6 +31,22 @@ Note that many current SEO plugins for WordPress also handle migration, but sinc
 
 No. If you need to update entries, reinstall HeadSpace2 or modify the values directly in the database.
 
+= What HeadSpace2 data is supported? =
+
+Currently the plugin will output:
+
+* custom post/page titles
+* meta keywords
+* meta descriptions
+* custom robots.txt declarations
+* JavaScript includes
+* Stylesheet includes
+* Raw header and footer content
+
+= Why isn't all HeadSpace2 data supported? =
+
+Mostly, I either didn't have time or didn't have a good example of how a particular feature was used. Contributions are welcome. :)
+
 == Changelog ==
 
 = 0.2 =