Add prequels/sequels & fix groups site specific metadata for fimfiction.net.

plugin-defaults.ini

@@ -1242,13 +1242,30 @@ extracategories:My Little Pony: Friendship is Magic
 
 ## Extra metadata that this adapter knows about.  See [dramione.org]
 ## for examples of how to use them.
-extra_valid_entries:likes,dislikes,views,total_views,short_description,groups
+extra_valid_entries:likes,dislikes,views,total_views,short_description,groups,groupsUrl,groupsHTML,prequel,prequelUrl,prequelHTML,sequels,sequelsUrl,sequelsHTML
 likes_label:Likes
 dislikes_label:Dislikes
 views_label:Highest Single Chapter Views
 total_views_label:Total Views
 short_description_label:Short Summary
 groups_label:Groups
+groupsUrl_label:Groups URLs
+groupsHTML_label:Groups
+prequel_label:Prequel
+prequelUrl_label:Prequel URL
+prequelHTML_label:Prequel
+sequels_label:Sequels
+sequelsUrl_label:Sequel URLs
+sequelsHTML_label:Sequels
+
+keep_in_order_sequels:true
+keep_in_order_sequelsUrl:true
+keep_in_order_groups:true
+keep_in_order_groupsUrl:true
+
+## Assume entryUrl, apply to "<a class='%slink' href='%s'>%s</a>" to
+## make entryHTML.
+make_linkhtml_entries:prequel,sequels,groups
 
 ## Some sites do not require a login, but do require the user to
 ## confirm they are adult for adult content.  In commandline version,