Document spoiler images

Author: lalcmellkmal

.gitignore

@@ -22,6 +22,7 @@ voice/*.mp3
 www/archive
 www/js/client*.js
 www/js/vendor*.js
+www/kana
 www/src
 www/thumb
 www/mid

README.md

@@ -10,6 +10,7 @@ Setup:
 * Copy hot.js.example to hot.js and configure
 * Copy imager/config.js.example to imager/config.js and configure
 * Copy report/config.js.example to report/config.js and configure
+* Clone [assets](https://github.com/lalcmellkmal/assets/) and copy the `kana` spoiler image folder as `./www/kana/` (or create your own!).
 * Run `npm install` to install npm deps and compile a few helpers
 * Run `node builder.js` to run an auto-reloading development server