Set `index` to 0 by default for `getShape()` and fixed the function description
Set `index` to 0 by default for `getShape()` and fixed the function description

this will help avoid basic issue/exception when migrating from 1.1.0

srbala/melonJS,MarkoIvanetic/melonJS,gopalindians/melonJS,srbala/melonJS,melonjs/melonJS,gopalindians/melonJS,rlugojr/melonJS,srbala/melonJS,rlugojr/melonJS,MarkoIvanetic/melonJS,TukekeSoft/melonJS,TukekeSoft/melonJS,gopalindians/melonJS,rlugojr/melonJS,melonjs/melonJS,TukekeSoft/melonJS