Rename '.cocoscript' to '.cocoascript'

[bysqtr]

I saw that the 'script.cocoscript' was (as you can see) incorrectly named to what it should be as 'script.cocoascript.' Thought I'd correct it, with the the file itself and the references to it in 'TemplateInfo.plist' and 'manifest.json' corrected with the right extension spelling.