More work on the archive. Start rendering conversations

config/filters/index.js

@@ -1,3 +1,4 @@
 module.exports = function(eleventyConfig) {
     eleventyConfig.addPlugin(require('./dates'));
+    eleventyConfig.addPlugin(require('./notes'));
 }

config/filters/notes.js

@@ -0,0 +1,14 @@
+function conversationLength(note) {
+    return note.replies.reduce((total, reply) => {
+        return total + conversationLength(reply);
+    }, 1);
+}
+
+module.exports = function (eleventyConfig) {
+    // Filter out notes so that it's only notes that aren't replying to a post
+    eleventyConfig.addFilter('topLevelNotes', function (notes) {
+        return notes.filter(note => !note.replyId);
+    });
+
+    eleventyConfig.addFilter('conversationLength', conversationLength);
+}