Update html-minifier's options.

[ci skip]

Gruntfile.js

@@ -316,13 +316,27 @@ module.exports = function (grunt) {
     htmlmin: {
       dist: {
         options: {
+          collapseBooleanAttributes: true,
           collapseWhitespace: true,
           conservativeCollapse: true,
-          minifyCSS: true,
+          decodeEntities: false,
+          minifyCSS: {
+            compatibility: "ie8",
+            keepSpecialComments: 0
+          },
           minifyJS: true,
+          minifyURLs: false,
           processConditionalComments: true,
           removeAttributeQuotes: true,
-          removeComments: true
+          removeComments: true,
+          removeOptionalAttributes: true,
+          removeOptionalTags: true,
+          removeRedundantAttributes: true,
+          removeScriptTypeAttributes: true,
+          removeStyleLinkTypeAttributes: true,
+          removeTagWhitespace: false,
+          sortAttributes: true,
+          sortClassName: true
         },
         expand: true,
         cwd: '_gh_pages',