Update preloader to load individual Kenney sprites

Also fix the placement of the loading bar.

README.md

@@ -42,3 +42,6 @@ If you'd like to run a simple web server, install http-server via `npm install h
 To upgrade Phaser CE run `npm upgrade phaser` (passing `--save` if you wish to update the package.json).
 
 Phaser TypeScript definitions can currently be found at https://github.com/photonstorm/phaser3-docs/tree/master/typescript
+
+## Credits
+Assets from [Kenney's Fish Pack](https://kenney.nl/assets/fish-pack).

src/assets/kenney_fishpack/License.txt

@@ -0,0 +1,21 @@
+	
+
+	Fish Pack
+
+	by  Kenney Vleugels (Kenney.nl)
+
+			------------------------------
+
+	License (Creative Commons Zero, CC0)
+	http://creativecommons.org/publicdomain/zero/1.0/
+
+	You may use these assets in personal and commercial projects.
+	Credit (Kenney or www.kenney.nl) would be nice but is not mandatory.
+
+			------------------------------
+
+	Donate:   http://support.kenney.nl
+	Request:  http://request.kenney.nl
+
+	Follow on Twitter for updates:
+	@KenneyNL