Fixes broken extension

There are two problems to use the extension. It isn't activated and I fixed the problems.

- Recently, Chrome requires additional `web_accessible_resources` section to `manifest.json`. I just added `jquery.min.map` to solve the problem.
```javascript
Denying load of chrome-extension://fhehiakkggdpbcgknhebkbhiadnpplag/components/jquery/jquery.min.map. Resources must be listed in the web_accessible_resources manifest key in order to be loaded by pages outside the extension. 
```
- Github's HTML has changed. I updated new selectors that is working.