Update README

Author: JuanKman94

README.md

@@ -2,12 +2,18 @@
 
 Privacy-focused, [todotxt] compatible, categorized TODO lists, powered with [SortableJS].
 
+[Try it out!](https://juankman94.github.io/mylist/)
+
+![Screenshot of webapp with dark color scheme](/assets/images/screenshot-dark.png)
+
 ## To Do
 
 * [x] add about/questions section
 * [x] add [Logo icon]
 * [x] add [service worker/a2hs]
 * [ ] add export controls: JSON & todotxt
+  * [x] JSON
+  * [ ] todotxt
 * [x] add controls to specify a back-end
 * [x] come up with a snapshot payload for back-end
 * [x] bottom nav
@@ -28,7 +34,7 @@ or Vue, HTML Custom Elements are used
 [Custom Elements v1: Reusable Web Components]: https://developers.google.com/web/fundamentals/web-components/customelements
 [Javascript Mixins]: https://javascript.info/mixins
 [JS Class Getters]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/get
-[Logo]: https://search.creativecommons.org/photos/cb8db7d0-d6f8-4477-8450-2fd9ed4f8dd9
+[Logo icon]: https://search.creativecommons.org/photos/cb8db7d0-d6f8-4477-8450-2fd9ed4f8dd9
 [service worker/a2hs]: https://developer.mozilla.org/en-US/docs/Web/Progressive_web_apps/Add_to_home_screen
 [svgeez]: https://github.com/jgarber623/svgeez
 [List icon]: https://search.creativecommons.org/photos/c51671ce-9cb3-4b15-bb47-529c3cb77875