Update docs, fix typo in background.js

CONTRIBUTING.md

@@ -0,0 +1,8 @@
+# Contributing to Wii Shop Channel Music
+
+The Wii Shop Music extension is intended to be a fun and simple browser extension. With that in mind, there are two main rules for contributing code or submitting issues:
+
+1. **No major new features.** I have no plans or desire to implement new major features, besides those already listed on the [issues page](https://github.com/corbindavenport/wii-shop-extension/issues).
+2. **No new music.** The extension already has 10 tracks included, and that will probably be it. The [ability to import custom music](https://github.com/corbindavenport/wii-shop-extension/issues/22) may be implemented in the future.
+
+Future development on the extension will mainly focus on bug fixes, shopping website additions, and any changes required to keep up with evolving browser standards.

README.md

@@ -1,6 +1,6 @@
-# ![Wii shop channel logo](https://raw.githubusercontent.com/corbindavenport/wii-shop-extension/master/img/icon48.png) Wii Shop Channel Music
+# Wii Shop Channel Music
 
-![gif](https://user-images.githubusercontent.com/42038239/152281142-e85c6313-b506-4bce-8d16-c82f9151892f.gif)
+![image](https://user-images.githubusercontent.com/3879063/151822369-ac4b1ea6-4c32-4918-a866-4cdf80758e43.png)
 
 
 This is a browser extension that plays the [Wii Shop Channel theme](https://www.youtube.com/watch?v=yyjUmv1gJEg) in the background when you visit a shopping website. You can also select the music from the 3DS eShop, DSi Shop, Wii Shop Banner/Home, Wii U eShop, Mii Channel (Wii or 3DS), and Coconut Mall.

js/background.js

@@ -9,7 +9,7 @@ if ('mediaSession' in navigator) {
     })
 }
 
-// Creat audio object
+// Create audio object
 var themeAudio = new Audio()
 themeAudio.volume = 0.5
 themeAudio.loop = true