Fixes #23

You the default behaviour will be to list the top 100
-c will allow you to filter by category
-l will list all categories and their id
-R will only show torrents uploaded in the last 48 hours **doesnt work when searching**
updated readme to reflect new options

```

pirate-get

pirate-get -c "Audio/Music"

pirate-get "Silicon Valley"

pirate-get -c "Video/TV Shows" "silicon valley"
```
Merge pull request #25 from vikstrous/develop/browse-top100-cat

Develop/browse top100 cat

Thanks everyone! I am going to merge this to master.

:shipit: