Client Tasks (#8889)

* tasks: markdown style, checkboxes. Misc fixes

* add filtering to tasks

* client tasks: complete filtering

website/client/directives/markdown.js

@@ -0,0 +1,8 @@
+import habiticaMarkdown from 'habitica-markdown';
+
+export default function markdown (el, {value, oldValue}) {
+  if (value === oldValue) return;
+
+  el.innerHTML = habiticaMarkdown.render(value);
+  el.classList.add('markdown');
+}