Documentation added to gruntfile

Gruntfile.js

@@ -90,6 +90,15 @@ module.exports = function(grunt) {
       }
     },
 
+    /** @TODO: PNG fallback for IE */
+
+/**
+ * 7 :: Run PHP through parser to create static HTML
+ *      (needed to include our critical css automatically).
+ *      This is not possible on most dynamic sites.
+ *      Search for alternative or extract critical CSS manually...
+ */
+
     php2html: {
       default: {
         options: {
@@ -103,6 +112,12 @@ module.exports = function(grunt) {
       }
     },
 
+/**
+ * 8 :: Extract critical CSS for a defined "above the fold" area.
+ *      If more finetuning is desired: alternative with more options
+ *      or external tool is needed.
+ */
+
     penthouse: {
       extract : {
         outfile : './css/critical.css',
@@ -113,6 +128,12 @@ module.exports = function(grunt) {
       },
     },
 
+/**
+ * 9 :: Automatically include CSS that is defined inline in the HTML file.
+ *      Include the ?__inline=true query parameter on assets that need to be
+ *      inlined. Example:
+ *          <link href="css/critical.css?__inline=true" rel="stylesheet" />
+ */
     inline: {
       dist: {
         options:{