Add index-template.html rewriting to rake :gem task.

Rakefile

@@ -94,6 +94,14 @@ def combine_js(html, dir)
   html.sub(js_section_re, '<script type="text/javascript" src="app.js"></script>')
 end
 
+# Modifies HTML to link app.css.
+# Doesn't modify the linked CSS files.
+def rewrite_css_links(dir, filename)
+  html = IO.read(dir + "/" + filename);
+  html = combine_css(html, dir, :replace_html_only)
+  File.open(dir + "/" + filename, 'w') {|f| f.write(html) }
+end
+
 # Compress JavaScript and CSS files of JSDuck
 def compress
   load_sdk_vars
@@ -118,12 +126,9 @@ def compress
   # Remove the entire app/ dir
   system("rm", "-r", "#{dir}/app")
 
-  # Concatenate CSS in print-template.html file
-  print_template = "#{dir}/print-template.html";
-  html = IO.read(print_template);
-  # Just modify HTML to link app.css, don't write files.
-  html = combine_css(html, dir, :replace_html_only)
-  File.open(print_template, 'w') {|f| f.write(html) }
+  # Change CSS links in print-template.html and index-template.html files
+  rewrite_css_links(dir, "print-template.html")
+  rewrite_css_links(dir, "index-template.html")
 
   # Concatenate CSS and JS files referenced in template.html file
   template_html = "#{dir}/template.html"