Fix and improve readme and extension comments

Author: Deraen

README.markdown

@@ -12,7 +12,7 @@ Currently _pegdown_ supports the following extensions over standard Markdown:
 * QUOTES: Beautifies single quotes, double quotes and double angle quotes (« and »)
 * SMARTYPANTS: Convenience extension enabling both, SMARTS and QUOTES, at once.
 * ABBREVIATIONS: Abbreviations in the way of [PHP Markdown Extra](http://michelf.com/projects/php-markdown/extra/#abbr).
-* ANCHORLINKS: generate anchor links for headers by taking the first range of alphanumerics and spaces.
+* ANCHORLINKS: Generate anchor links for headers by taking the first range of alphanumerics and spaces.
 * HARDWRAPS: Alternative handling of newlines, see [Github-flavoured-Markdown]
 * AUTOLINKS: Plain (undelimited) autolinks the way [Github-flavoured-Markdown] implements them.
 * TABLES: Tables similar to [MultiMarkdown](http://fletcherpenney.net/multimarkdown/) (which is in turn like the [PHP Markdown Extra](http://michelf.com/projects/php-markdown/extra/#table) tables, but with colspan support).
@@ -29,7 +29,9 @@ Currently _pegdown_ supports the following extensions over standard Markdown:
     * [ ] open task item
     * [x] closed or completed task item.
     * [X] also closed or completed task item.
-* EXTANCHORLINKS uses all text of the header for ANCHORLINKS, spaces and non-alphanumerics replaced by `-`, multiple dashes trimmed to one.
+* EXTANCHORLINKS: Generate anchor links for headers using complete contents of the header.
+    * Spaces and non-alphanumerics replaced by `-`, multiple dashes trimmed to one.
+    * Anchor link is added as first element inside the header with empty content: `<h1><a name="header"></a>header</h1>`
 
 Note: _pegdown_ differs from the original Markdown in that it ignores in-word emphasis as in
 

src/main/java/org/pegdown/Extensions.java

@@ -137,7 +137,7 @@ public interface Extensions {
     static final int FORCELISTITEMPARA = 0x00080000;
 
     /**
-     * Force List and Definition Paragraph wrapping if it includes more than just a single paragraph
+     * Allow horizontal rules without a blank line following them.
      */
     static final int RELAXEDHRULES = 0x00100000;
 
@@ -147,7 +147,9 @@ public interface Extensions {
     static final int TASKLISTITEMS = 0x00200000;
 
     /**
-     * GitHub style task list items: - [ ] and - [x]
+     * Generate anchor links for headers using complete contents of the header.
+     * Spaces and non-alphanumerics replaced by `-`, multiple dashes trimmed to one.
+     * Anchor link is added as first element inside the header with empty content: `<h1><a name="header-a"></a>header a</h1>`
      */
     static final int EXTANCHORLINKS = 0x00400000;