Use https URLs (romannurik#127)

Also small typo fix.

Author: ozbek

README.md

@@ -1,13 +1,13 @@
 Android Asset Studio
 ====================
 
-**[Open the Android Asset Studio](http://romannurik.github.io/AndroidAssetStudio/)**
+**[Open the Android Asset Studio](https://romannurik.github.io/AndroidAssetStudio/)**
 
-**[See the older version](http://romannurik.github.io/AndroidAssetStudio/older-version/) if you're having trouble with the new version**
+**[See the older version](https://romannurik.github.io/AndroidAssetStudio/older-version/) if you're having trouble with the new version**
 
 A web-based set of tools for generating graphics and other assets that would eventually be in an Android application's res/ directory.
 
-Currently available asset generators area available for:
+Currently available asset generators are for:
 
 - Launcher icons
 - Action bar icons