Dino dex 2nd Refactor

DinoDex refactor based on comments from previous pull request.

The DinoDex has a command line interface. Run the "main.rb" script to initialize the CLI.
The constants on lines 28-31 should be moved outside the method and into the class body. However, you can get away without using them at all. Just take the union of all the filters. For example, if you call `continent_filter` with `filter = 'joe'` it will just return an empty array. So `process_filter` could be re-written as:
```
[period_filter(dinos, filter),
attribute_filter(dinos, filter),
...
].flatten
```