Fix "main" in bower.json

Right now "main" attribute in bower.json points to can.jquety.js:

```
"main": "can.jquery.js"
```

It is actually correct? And shouldn't it point to index.js?

Start by reading bower.json and checking whether can.jquery.js and index.js exist in the repository and which file is intended as the package entry point. Confirm the expected Bower entry before changing the main value; done means the metadata points to the correct existing entry file.

Written by the indexing model from the issue text.