Chess Game exercise, Ruby track

One of the examples in the Chess Game exercise’s README in the Ruby track needs to be corrected.

Where it says: "Hello World"[6..-4] # =>"Wor"
should actually be: "Hello World"[6..-4] # =>"Wo"

Also, where it says:

Define the `Chess::Ranks` and `Chess::Files` constants

It should actually say:

Define the `Chess::RANKS` and `Chess::FILES` constants

As the constants are referenced in all caps from the test. They also need to be amended in the 2 code examples following the paragraph.

[Chess game]: Various fixes by meatball133 · Pull Request #1577 · exercism/ruby · GitHub merged to address this.

Thank you @carmeta .

Thank you @kotp

All the credit goes to @Meatball , really! But you are welcome!